The god of rain, also known as the rain master, is worshipped with the god of wind and has a very ancient origin. According to the Classic of Mountains and Seas and the Great Wilderness North, Chi You raised an army to fight against the Yellow Emperor and asked the god of wind and rain to bring heavy rain. The Classic of Rites and the Grand Sacrifice Officer says: “The Nanliao sacrifice is offered to the gods of the sky, the gods of life and death, the god of wind and the god of rain.”
While the Chinese regarded the Big Dipper as the Wind God, they regarded the Pleiades as the Rain God. Cai Yong's Dunan says, “The Rain God is the Pleiades. Its image is in the sky and it can bring rain.” The Book of Songs says, “The moon is in the Pleiades, causing torrential rain.” “Dragon Fish River Map” in Volume 6 of ‘Comprehensive Collection of Weishu’: ‘The star Tai Bai in the sky is in charge of the army, and its essence becomes the god of the rain master.’ ‘The Book of Changes: The Master hexagram’ says: ‘The master is the crowd.’ ‘Customary Meaning: Rituals’ says: ”Among the multitude in the earth, there is nothing like water. Thunder can be heard a hundred li away, and the same is true of the wind. As for Mount Tai, it rains all over the world in no time, unlike thunder 
wind, its virtue is widespread, so rain alone is called the master. The god of the year of the ox is the rain master, so the rain master is worshipped on the day of the ox in the northeast, where earth prevails over water, representing the element of fire. It can be seen that at the time, the rain god had already been included in the national sacrificial rites.
Later, the rain master was incorporated into the Daoist pantheon as either a dragon, a ram, or a pine tree. “Baopuzi: Ascending and Wading”: “On the day of the ox in the mountains, there are those who call themselves the rain master, and they are dragons.” “The Origin of the Three Religions and the Search for Gods” vol. 7: ‘The Rain Master is Shangyang. Shangyang is a divine bird with one leg that can grow big or small. It can dry up the seas and oceans by sucking them dry. The Rain Master is also a god.’ ‘The Search for Gods’ vol. 1: ”Chi Song Zi was the Rain Master in the time of Shennong. He took ice jade powder to teach Shennong. He could enter fire without burning. He went to Kunlun Mountain and often entered the stone room of the Queen Mother of the West, going up and down with the wind and rain. The young girl of the Yan Emperor chased after him, and she also became immortal, and they both left. During the time of the High Emperor, he once again became the Rain Master and wandered among mortals. This is the origin of the Rain Master of today.” Also, in Volume 1 of ‘A General History of Immortals’: During the time of Shennong, the rivers ran dry and the mountains collapsed, all becoming sand and gravel. Even the sky did not rain for a long time, and the millet and sorghum withered everywhere. There was a wild man, with a strange appearance and crazy speech, wearing a straw with a straw collar, a leather skirt tied around his waist, unkempt hair and bare feet, fingernails as long as claws, covered in yellow hair all over, holding a willow branch in his hand, singing and dancing wildly, saying, “My name is Chisongzi. I stayed in Wangwu for many years cultivating, and then travelled with the real immortal Chizi to Hengshan in the south. The immortal often transformed into a red flying dragon, coming and going. I also transformed into a red basilisk and chased after him. I paid homage to the primordial gods and saints. Because I could follow the wind and rain up and down, I was named the Rain Master and was in charge of bringing rain.”
The folk also had their own views on the rain master. The Han people regarded Xuanming as the rain master. The “Fengxi Tongyi · Sidian” and “Spring and Autumn · Zuo Shi Zhuan” say: Gong Gong's son was the master of Xuanming. Zheng Daifu Zichan prayed to Xuanming. The rain master. Because Xuanming was the ancient water official among the five officials, and water and rain are related, he was called the rain master.
There are also those who regard Pingyi as the rain master. In the Chu Ci (Odes of Chu), the sky asks why it is raining. Wang Yi's commentary says: “Jiang is the name of the rain master.” In the Guangya (Broad Rhymes), the rain master is called Jiang Yi. Jiang Yi is also called Ping Yi. In Sima Xiangru's “Daren Fu” (Ode to a Nobleman), Jiang Yi is summoned to punish Feng Bo and the rain master. In Cao Zhi's “Luo Shen Fu” (Ode to the Goddess of the Luo River), Jiang Yi collects the wind and the waves of the river calm down.
During the Tang Dynasty, Li Jing was also worshipped as the god of rain. The Shanxi Tongzhi records that the temple of the god of rain and wind is located in Siwang Village, Yicheng County. The god is Li Jing, the Marquis of Tangwei. This probably stems from the story of Li Jing's rain-making in the book Tang Yishi. Legend has it that Li Jing was once travelling in the mountains and stayed at a civilian's house for the night. In the middle of the night, a woman handed him a water bottle and said, “Heaven has commanded you to rain, so please do the job for us.” A servant led a green steed up to him and said, “You must drip three drops of water from the mane of the horse. After Li Jing got on the horse, he was about to drip the water, but unexpectedly the horse became frightened, snorted, and leaped into the air, dripping several drops of water from the bottle. The next day, there was a heavy rain in the area, which solved the drought. The people were grateful and built a temple to worship him.
In addition, the “Book of Strange Things” also says that the Rain Master is Feng Xiu, also known as Shude and Chen Huafu. The “Collection of Explanations and Truths” also depicts his image: a bearded man, holding a bowl in his left hand, with a dragon inside, and sprinkling water with his right hand, called Chen Tianjun, the Rain Master.
 

    雨神亦称雨师，其信仰与风神一样，起源甚古。《山海经·大荒北经》蚩尤作兵，伐黄帝，请风伯雨师，纵大风雨。《同礼·大宗伯》：“以楠燎祀司中、司命、风师、雨师。”
汉人在以箕星为风伯的同时，则以毕星为雨师。蔡邕《独断》曰：“雨师神，毕星也。其象在天，能兴雨。”《诗》云：“月离于毕，俾滂沱矣。”《重修纬书集成》卷六《龙鱼河图》：“天太白星主兵，其精下为雨师之神。”《易·师卦》曰：“师者众也。”《风俗通义·祀典》称：土中之众者莫若水，雷震百里，风亦如之。至于太山，不崇朝而遍雨天下，异于雷 
风，其德散大，故雨独称师也。丑之神为雨师，故以乙丑日祀雨师于东北，土胜水为火相也。可见当时雨神已被列入国家祀典。
后来雨师被道教纳入神系，或云为龙，或云为商羊，或云为赤松子。《抱朴子·登涉》：“山中辰日有自称雨师者，龙也。”《三教源流搜神大全》卷七：“雨师神，商羊是也。商羊神鸟，一足，能大能小，吸则溟渤可枯，雨师之神也。”《搜神记》卷一：“赤松子者，神农时雨师也。服冰玉散，以教神农。能入火不烧。至昆仑山，常入西王母石室中，随风雨上下。炎帝少女追之，亦得仙，俱去。至高辛时，复为雨师，游人间。今之雨师本是焉。”又《列代神仙通鉴》卷一神农时，川竭山崩，皆成沙碛，连天亦几时不雨，禾黍各处枯槁，有一野人，形窖古怪，言语颠狂，上披草领，下系皮裙，蓬头跣足，指甲长如利爪，遍身黄毛覆盖，手执柳枝，狂歌跳舞，曰：“予号赤松子，留王屋修炼多岁，始随赤真人南游衡岳。真人常化赤色神首飞龙，往来其问，予亦化一赤虬，追蹑于后。朝谒元始众圣，因予能随风雨上下，即命为雨师，主行霖雨。”
民间对雨师亦有自己的看法，汉人以玄冥为雨师。《风惜通义·祀典》《春秋·左氏传》说：共工之子，为玄冥师。郑大夫子产禳于玄冥。雨师也。因玄冥是古代五行官中的水官，水与雨相通，故被称为雨师。
又有以萍翳为雨师的。《楚辞·天问》蒋号起雨。王逸注曰：“蒋，萍翳，雨师名也。”《广雅·释天》雨师谓之蒋翳。萍翳又称屏翳。司马相如《大人赋》 召屏翳，诛风伯，刑雨师。曹植《洛神赋》屏翳收风，川后静波。
唐朝时还以李靖为雨师。《山西通志》风雨神庙，在翌城县四望村。其神唐卫公李靖。这大概源于《唐逸史》中李靖行雨的故事。相传李靖曾经远行于山中，夜晚寄宿于民夫家中。半夜，一妇人将一个水瓶递给他说：天命行雨，烦汝代劳。一佣人牵一青骢马至，对李靖说：汝以水自马鬃下，三滴乃止，慎勿多滴。李靖上马后，正准备滴水，不料马惊，咆哮跃空，瓶中水一连数滴，次日当地一场大雨，解决了旱情，民感其恩，立庙祀之。
另外《事物异名录》还说雨师为冯修，号树德，又名陈华夫。《集说诠真》中还描绘了他的形象：乌髯状汉，左手执盂，内盛一龙，右手若洒水状，称之日雨师陈天君。