Abstract: The genetic polymorphism and differentiation were analyzed in Wild boar， Duroc，Landrace and crossbred populations of Wild boar×Duroc and Wild boar×Landrace with five structural genes by PCR-RFLP and PCR-SSCP.The results showed as follows: (1) In the above detected populations，the mean heterozygosity and PIC indicated that Wild boar presented low polymorphism while other populations had mediate polymorphism.(2) The results indicated that 17.9% and 82.1% of total variation were respectively from between and within three populations including Duroc， Wild boar and Wild boar×Duroc， while 27.1% and 72.9% of total variation were respectively from between and within three populations including Landrace， Wild boar and Wild boar×Landrace， so the genetic differentiation in Wild boar，Duroc，Landrace and their crossbred populations were at the mediate level(Fst＞0.15). (3) Distance of Reynolds′ indicated that Duroc and Wild boar with larger genetic distance will bring greater heterosis than Landrace and Wild boar.