During the Wei, Jin, Southern and Northern Dynasties, even though there were frequent wars that the society was in turmoil and the economic development was stagnated, qigong continued to develop without a standstill because dao yin and health cultivation practices were popular among the scholar-bureaucrats.
In the beginning of Jin Dynasty, Wei Hua-cun (魏华存) wrote the Classic of Yellow Courtyard(Huáng Tíng Jīng, 黄庭经), in which she used seven-character verses to summarize and describe the physiology theories and keys of the Taoist qigong from before her time. It was written on the basis of the health cultivation principles from Taoism plus the various theories from medicine, and has been regarded as a classic ever since, bringing a great impact to generations after.
Ge Hong (葛洪), a medical scientist and Taoist philosopher in Eastern Jin Dynasty, had a lot of contributions to the qigong theories. He wrote The Teachings of Master Bao Pu/Bao Pu Zi (Bào Pú Zĭ, 抱朴子), which is a summary and a systematic study of the Taoist theories about health cultivation. It suggests that qigong practices can be classified into two: 1) Inner cultivation, which is to cultivate the mind and personality (training of the mind). 2) Outer cultivation, that is to cultivate the physical body, outer cultivation includes practices such as qi moving, dao yin, massage and others similar. These theories and methods from the book have great influence on the development of qigong.
Tao Hong-jing (陶弘景) was a famous Taoist philosopher and medical scientist living around the time of Qi and Liang during Southern Dynasty, his view and study of qigong and health cultivation are mostly written in the book Records for Cultivating Mind and Prolonging Life (Yăng Xìng Yán Mìng Lù, 养性延命录). In the chapter Treating Disease by Taking Qi (Fú Qì Liáo Bìng Piān, 服气疗病篇), different methods of breath regulation are introduced, and there are six specific exhalation methods for treating different diseases, which is what we now call Liu Zi Jue, including “Chui (吹), Hu (呼), Xi (唏), He (呵), Xu (嘘), Si (呬)”. Also, the text description of how to practice Wu Qin Xi (The Five Animals Frolic) was first seen in this book in the chapter Daoyin and Massage (Dăo Yĭn Àn Mō Pian, 导引按摩篇).
 “Southern Dynasty” is the collective term for four short consecutive dynasties in China from 420 D.C to 589 D.C., Qi and Liang are two of the four.