The Researches were conducted with a non complete diallel of 22 crosses between one group of rice cultivars LA110, Jasmine 85 and another group of rice cultivars Teqing, Katy, Mars, LaGrue, Newbonnet to identify the inheritance of rice blast ( Pyricularia grisea ) resistance to three rice blast races IB 33, IB 45 and IE 1 of the USA. The parents, F 1 and F 2 were tested for their resistance to these races in the greenhouse at Stuttgart, Arkansas in the USA during October 1995 to November 1997. Parents LA110 and Jasmine 85 in the first group were resistant to all races. Teqing in the second group was resistant to all the three races. Katy was resistant to two races IB 45 and IE 1. Mars was only resistant to IE 1. LaGrue was susceptible to all the three races. Newbonnet was susceptible to two races IB 33, IE 1. The resistance was controlled by dominant genes to all races and all F 1 were resistant to all the three races. There were allelic genes to race IB 33 in the crosses between resistant parent LA110 and resistant parent Jasmine 85, and to race IE 1 in the crosses between LA110 and resistant parent Teqing or Jasmine 85, and also to race IE 1 in the crosses between Jasmine 85 and Teqing. It might be three dominant resistance genes to race IB 33 in the crosses between LA110 or Jasmine 85 and Teqing. The resistance was controlled by two dominant independent resistance genes to race IB 45 in the crosses among resistant parents LA110 and Teqing, Katy, Newbonnet or Jasmine 85, and also to race IB45 in crosses among resistant parents Jasmine 85 and Teqing, Katy or Newbonnet; and to race IE 1 in the crosses between resistant parents LA110 and Katy or Mars; and also to race IE 1 in the crosses between resistant parents Jasmine 85 and Katy or Mars. It might be two dominant complementary resistance genes controlling inheritance to race IB 33 in the crosses between resistant parent LA110 or Jasmine 85 and susceptible parent Mars; and also to race IB 45 in the crosses between LA110 and Mars. The resistance could be controlled by a single dominant resistance gene to race IB 33 in the crosses between LA110 or Jasmine 85 and susceptible parent Katy, LaGrue or Newbonnet, and to race IB 45 in the crosses between LA110 and susceptible parent LaGrue, and to race IB 45 in the crosses between Jasmine 85 and susceptible parent Mars or LaGrue; and to race IE 1 in the crosses between LA110 or Jasmine 85 and susceptible parent LaGrue or Newbonnet. The inheritances were the same between the cross of two parents and their reciprocal. It was discussed to use 3 resistant cultivars of LA110, Teqing and Jasmine 85 in rice breeding for resistance to blast in the southern part of the USA.