The multilocus mixed mating model and correlated mating model were used to anlyze the mating system of a natural Hevea brasiliensis (Willd. Ex Adr. Of Juss) population from the State of Acre Seeds of 37 mother trees were planted in a progeny test in Selviria, state of Mato Grosso do Sul. Six to 24 individuals per family were evaluated in allozyme electrophoretic analysis. Significant differences between pollen and ovule frequencies were detected in three loci, indicating that the pollen pool was heterogeneous among trees. The multilocus outcrossing rate was estimated at 0.962, indicating allogamy predominance in the population. The correlation of paternity was high (0.351), indicating that 34;of outcrossing progenies are full-sibs. The estimate of the mean coefficient of coancestry among plants within families was 0.177, confirming the mixture of different degrees of relatedness within families.