The Mechanism for sorting out the covariance effect is known as the covariance analysis. The sorting out of regression and correlation effect is an obvious application of the covariance analysis. The result of Do population by age groups (15 age interval) from 1966 census and from, 1970 Census has been applied to analyzing covariabiltiy by the analysis of covariance. The results are as follows. The significance of the regression of 1970 population on 1966 population is assured as F=116.5. There is a significant difference between mean of each age groups(F=88.1). There is very little evidence of significant heterogeneity of regression between age group. (F=0.72).