The positive factors in Japan and South Korea free trade zones are mainly：the use of the three countries are highly complementary to each other more closely established industrial division system，low trade volume three countries to provide development space for CJK FTA，demand and investment liberalization in the region provide the impetus for CJK FTA. Negative factors mainly：the difference of the three trade imbalance and dependence have some negative impact on the construction of Japan and South Korea FTA，China and Japan，there is a serious imbalance in the bilateral trade in national trade balance，in Japan and South Korea differences on regional cooperation demands and competition for dominance，Japan and South Korea work together to weaken the strength of the establishment of FTA.