Abstract: Discusses the formation of yearly input output table through a series of discrete input output tables in order to make use of the static input output theory. Based on a systematic study on the basic and stage RAS, the procedure of blocked RAS application is put forward. In the procedure, the direct expense coefficient matrices A are first separated according to different types of changes into blocks, and RAS is applied to each block. Comparison of the 3 approaches shows that the blocked RAS behaves better than the other two, while the 2 stage RAS operates better than the one using basic RAS.