The variables in LISREL are classified by the following three criteria: (1) endogenous or exogenous, (2) observed or latent, (3) structural or error. Generally, LISREL is easier to use than the B & W model (Bentler & Weeks 1980), because the variables in the B & W model are defined from (1) only. But, in LISREL, the observed variables simultaneously affected by the endogenous and the exogenous latent variables can not be treated. So, in this study, a new expression of covariance structure is proposed. The expression explains the variables from the above three points of view, and includes the observed variables that are simultaneously affected by the endogenous and the exogenous latent variables. The practical application with this expression is shown by using standardized data of Japanese ITPA.