Abstract:The genetic diversity in fifteen populations of Pinus, yunnanensis Franch. were studied by starch gel electrophoresis in the present work. Fourteen enzyme systems, presumably coded by 33 allozyme loci and their alleles were scored, and 32 were polymorphic with only one monomorphic locus (Dia - 4). The loci with three alleles are Lap-1, Lap-2, Aat-3, Skd-1, Skd-2, Adh-l, Adh-3, Gdh, Pgd-1, Pgm-1, Pgm-3, Pgi-l, P^-3, Mdh-l, Me, Idh-l, Idh-2, G6pd, Dia-1, Tpi-1,Tpi-2, Tpi -3 and Tpi-4, those with four alleles are Skd-3,Adh-2, Pgd-2, Mdh-2, Mdh -3, Mdh - 4 and Dia - 2, and those with five alleles are Aat - 1 and Dia -3.