In order to figure out the mating pattern of natural population of Pteroceltis tatarinowii Maxim.， amplification reaction of DNA from leaf of progenies of 10 lines in Qingtan Temple of Shandong was carried out by using SSR molecular marker technology. On the basis， singlelocus outcrossing rate， multilocus outcrossing rate， biparental inbreeding coefficient， parental inbreeding coefficient， and inbreeding depression value of each line were analyzed. The results show that means of singlelocus outcrossing rate and multilocus outcrossing rate of each line in this natural population are 0.959 and 0.987， respectively， and multilocus outcrossing rate of most lines is higher than their singlelocus outcrossing rate. Mean of biparental inbreeding coefficient is 0.028， indicating that there is a certain degree of inbreeding among each line in this natural population. Mean of parental inbreeding coefficient is -0.066， indicating that heterozygotes in this natural population are excess in general. In addition， inbreeding depression values of 4 lines are relatively high （1.793-4.588）. Combining biological characteristics of P. tatarinowii， outcrossing is mainly in mating system of this natural population of P. tatarinowii， and there is a relatively high inbreeding depression. Therefore， in order to prevent population depression， measures of in situ and ex situ conservation and so on are recommended to prevent inbreeding.