A national demographic policy would have important influence on the application of human resource and economic development of a nation. The previous studies adopted qualitative, descriptive-intuitive, and econometric approach to investigate the effectiveness. However, those approaches could not exactly examine the effectiveness of policy. Therefore, this study provides the intervention model to directly examine the effects of pronatalist or denatalist policies on fertility. The results states that the demographic policies presented in 1964, 1983 and 1992 do not have any significant effect on diminishing or increasing fertility. This study also provides suggestions for the related policies to boost the fertility.