Abstract:The relations among rooting traits and contents of endogenous hormone,total phenolic acid,nutrient substance of four elite Japanese larch (Larix kaempferi) clones were studied.The results showed that:(1)There were significant differences in the rooting ability of cuttings amongst different clones.‘Rikuan17-3-1’ and ‘Rifu27-3-1’ were easy rooting clones,which the rooting rate reached 90%.While ‘Ricao103-3-1’ and ‘Ricao82-4-3’ was difficult rooting clones,which the rooting rate was lower than 20%.(2)The content of ABA in cuttings was increasing with time prolonging,and significant differences had been found between difficult rooting clones and easy rooting clones,there was a strong correlation between ability and ABA content.The content of Z and total phenolic acid was decreasing with time prolonging,and had a negative influence on the rooting.The content of total nitrogen was decreasing until stabilization with the time prolonging,while no significant relations with rooting ability.(3)(IAA+Z)/ABA was decreased with the time prolonging,and the rate in easy rooting clones was lower than that in difficult rooting clones.(IAA+Z)/ABA and total phenolic acid may be used as a standard to express the rooting ability of Japanese larch.