Abstract:Twelve high resistant transgenic rice lines with 1-4 extra anti-fungus genes were crossed with 2-3 male-sterial rice lines. Heterosis analysis of resistance of transgenic hybrid rice to sheath blight was studied with 3 resistance indices under the condition of artificial inoculation in field.The results showed that the resistance of transgenic hybrid rice had positive correlation with transgenic male parentage and the value of broad hereditary capacity was 0.52-0.83. Among 29 hybrid combinations, 5 combinations had significantly negative heterosis over lower parents (HLP), but the average value of HLP of all combinations was 35.01%-50.79%, was positive. The average negative heterosis over control (HC) of all combinations was strong, the value was-57.60%--31.23%. The 38% hybrid combinations had remarkable negative HC. It indicated that the resistance of transgenic hybrid rice was usually lower than its transgenic male parents, but it still was resistant.The strong heterosis hybrid combinations with high resistance could be selected among the combinations.