This study focuses to analyze changes of traits of production network between industries in Korea and Japan empirically by time series analysis. The way of analysis is to measure Backward Linkage Effect by calculating input coefficient and Leontief multiplier. Especially, from 2000 to 2008 when American financial crisis started were analyzed. The changes of both countries` production technologies structures were measured. In other words, import dependence structures for intermediary goods were measured. Through it, it was reviewed how production network changes of each country in each industry affect the other partner countries. As a result of analysis, the weight of production network in Korea in each industry for Japan since 2000 was light. However, it got more important. The structural relation that Japanese industry productions increase causes Korean industry productions increase unlike phenomenon in past gets stronger. Especially, unlike 1990 to 2000 in the past, it is something remarkable that the weight of Korean industry production network becomes more important in general machines which are core export industry to Japan in 2008, metal products, transportation machines, precise machines, electronics, electronics, etc.