Objective The medical model should be bio-psycho-social medical model, a large number of latent variables are involved in many medical scientific researches. The application of linear and nonlinear structural equation models in the occupational psychology and psychiatry had been explored in this paper. In order to describe developmental processes at both the inter- and intra-individual levels, latent growth model had been applied to analyze the longitudinal data. Consequently this paper had provided scienti...