He recuperated slowly, and was apprenticed to a well-known artist, Wang Xiangchan 汪香禪, in hopes that simple jobs like grinding ink would help his health.

By the age of eighteen, Cheng was teaching poetry and art in Beijing and within a few years had become a successful artist whose works were in demand.

His aunt's friend Cai Yuanpei gave him a letter of introduction that led him to Shanghai, where he became acquainted with influential figures including Wu Changshuo, Zheng Xiaoxu, Xu Beihong, and Zhang Daqian.

He took a position as the Dean of the Department of Traditional Painting at the prestigious Shanghai College of Art, which was headed by Liu Haisu.

In his twenties, Cheng developed lung disease (believed to be tuberculosis partly from exposure to the chalk dust from the school blackboards).

Cheng retired from teaching and devoted himself for several years to the study of tai chi, traditional Chinese medicine, and literature.

He demanded to be put in contact with the person who wrote it, as the sophistication and erudition of the prescription showed exceptional talent and competence.

Dr Song was the twelfth generation of physician in his family; his medical school had a formidable collection of traditional medicines.

He wrote the manuscript for his Thirteen Chapters during this period, and showed them to his elder classmate Chen Weiming, who gave it his imprimatur.

He continued his career as a physician and as a teacher of his new tai chi form, as well as actively practicing painting, poetry, and calligraphy.

He started the Shih Chung T'ai Chi Association in Taipei, where many now well-known students including (Benjamin Lo, Liu Hsi-heng, Hsu I-chung, Qi Jiang Tao, Robert W. Smith, T. T. Liang, William C. C. Chen, Huang Sheng Shyan and others[citation needed]) trained with him.

In 1964, Cheng moved with his wife, two sons, and three daughters to the United States, where he taught at the New York T'ai Chi Association at 211 Canal Street in Manhattan.

He then founded and taught at the Shr Jung T'ai Chi school at 87 Bowery in New York City's Chinatown section, with the assistance of his six American senior students, known as the "Big Six": Tam Gibbs, Lou Kleinsmith, Ed Young, Mort Raphael, Maggie Newman, and Stanley Israel.

While living in New York City, Cheng often spent several hours in the early afternoons studying or teaching classes of three or four students in the C. V. Starr East Asian Library at Columbia University, usually in a small, mahogany-panelled loft above the main floor.

Cheng wrote numerous books and articles on a variety of subjects, including commentaries on the I Ching, the Tao Te Ching, the Analects of Confucius, his original works of poetry, essays, medicine, and several art collections.https://chengmanching.wordpress.com/writings./ In 1967 in collaboration with Robert W. Smith, and T. T. Liang, Cheng published "T'ai Chi, the Supreme Ultimate Exercise for Health, Sport and Self-defense," which was his second tai chi book in English.

Cheng also produced several tai chi films, and some of his classes and lectures were recorded and in later years released on DVD.

His shortened form became extremely popular in Taiwan and Malaysia, and he was one of the earliest Chinese masters to teach tai chi publicly in the United States.

Upon his return to New York, Cheng taught at the new location, 87 Bowery, sending an unmistakable message of inclusiveness and rejecting the insularity that was traditional in the Chinese martial arts community.

While Prof. Cheng was teaching in New York, he asked Fred Lehrman to help initiate schools in Milwaukee WI, Minneapolis MN, Gainesville FL, Boulder CO, and Halifax, Nova Scotia.