Abstract: Genetic diversity of M18 parent,Large-female parent,Medium-female parent,Small-female parent and Muscovy ducks was studied using eight microsatellite markers in order to analyze the relationship of microsatellite polymorphisms and the heterosis of growth traits.The result indicated the average effective allele was 2.881,the average polymorphism information content was 0.6331,and the average gene heterozygosity was 0.5181.The genetic distances between muscovy duck with Large-female parent,Medium-female parent,Small-female parent were 0.4452,0.3623,0.3671 and 0.3224 respectively.According to the standard genetic distances,forecast the heterosis of mule duck by the model of logarithmic curve.There were no significant differences between the predicted results and the experimental determination by T test which demonstrated that using genetic polymorphism of microsatellite markers to forecast the heterosis of white-weather mule duck is practicable.