With KEN NONG-4 as experimental material, the text studys that Chemical control seed coating (HK) and general seed coating (ND) impacts upon lateral root anlage Initiating of soybean seeding, meanwhile analyzes dynamic changes of plant endogenous hormone contents in the course of lateral root anlage Initiating by experiment of vertical plank germination. The results show: (1) After soybean seed is treated with seed coating, The length of lateral root anlage Initiating area obviously increases in contrast with control (seed which is not coated with agent is regarded as control; shortened form is CK).The order is from greatness to smallness in turn as follow: HK＞ND＞CK. (2) Initiating progress of lateral root anlage is quickened when seed is treated with seed coating. General trend is as follow: HK＞ND＞CK. By variance analysis, treatment and control has obvious difference. (3) Initating status of lateral root anlage is definite related with contents of endogenous hormone. Occurring of lateral root is as the result of some endogenous hormone corresponded and playing manysided role, especially IAA plays important role in the cause of inducing to occurring of lateral root anlage. (4) The use of seed coating may elevate the number of lateral root anlage occurring and shorten the time of lateral root anlage occurring, especially the effect of Chemical control seed coating is better.