Oil taken from the bellies of live or dead wood frogs can be dried in the sun, then soaked and taken. This kind of oil is called thread oil. The smell is very small. When it is taken out, it will be pulled out and become as thick as a piece of wool, 10 cm long. It can be put on iron wire or iron wire to dry, and it can be dried in one day, preferably thoroughly, and it is easy to store. After soaking, it can be taken by steaming, boiling, adding vegetables and crystal sugar or directly. Generally, a person's daily consumption is a quarter of the oil production of a wood frog.

China Rana chensinensis, referred to as Rana chensinensis for short, is distributed in most areas of Xiaoxing 'an Mountains, the abdomen of Zhangguangcailing Mountains and Changbai Mountains. People in Hongkong and Guangdong are called China Rana, which belongs to rare amphibians. In spring, China wood frogs come out of the river, mate and breed in the pond, and then prey on insects in the Woods. The oviduct of female China Rana chensinensis is called Rana chensinensis oil.

The traditional method of oil extraction is to dry Rana chensinensis for 7 days to 10 days. After drying, oil was obtained. China Rana chensinensis oil is in the shape of a block. Because the oviduct of China Rana chensinensis is linear, and the oil is obtained from living body, it will not cause secondary pollution. The oil body is clean, free of impurities and peculiar smell, and practical and convenient. It is generally favored by the south, while the north. Rana chensinensis oil can improve human immunity. Rana chensinensis oil has many functions and is suitable for men, women and children. Women can eat beauty beauty, nourish yin and liver, regulate endocrine and delay aging; Men can resist fatigue, nourish yin and strengthen yang, tonify kidney and replenish essence. It is a reliable regulator for anti-aging and improving immunity.