A survey of allozymic alleles and genetic diversity was conducted for ten natural populations of Picea asperata Mast. originating from the mountains of Southwest China. A total of twenty-seven alleles at seventeen loci were observed. Ten of the loci were found monomorphic. Our results showed that the populations sampled were characterized by low genetic diversity (mean He = 0.096) and a low level of inbreeding (mean Fis = 0.005). The UPGMA tree of genetic relationships indicated that there was significant differentiation among populations. The coefficient of genetic differentiation among populations, based on Fst, equaled 0.311. Such extensive inter-populational differentiation detected in P. asperata could have resulted from allele frequency divergence among populations, particularly, in one population. Introgression from another species, variation in environmental conditions, and differing selection pressures could be some of the factors attributing to significant differences among populations. In addition, our results showed that the geographic and genetic distances were not correlated in the populations of P. asperata. Based on the genetic information obtained, we concluded that monitoring appropriate genetic markers may be an effective means of identifying potential genetic changes occurring during forest tree evolution.