He was generally acknowledged as one of the pioneers and founders of modern mechanics undertakings in China. His major research activities include; the intrinsic theory of plates and shells, the analysis of large deflection of thin plates and shells, the analysis of corrugated pipes, mechanics of armour penetration, singular perturbation methods, variational principles and generalized variational principles, finite element methods as well as the measurements of atmospheric electricity, spectral analysis of rare-earth elements, wave guide theory, lubrication theory, the development of high-energy batteries, his macro-coding of Chinese characters, etc. The joint work with J. L. Synge on the intrinsic theory of plates and shells is considered as a pioneering classical work in solid mechanics and his successive approximation method of treating large deflection problem is now named as "Chien's method".