Abstract:The research was conducted to reveal the regular of resistance to sheath blight and chitinase activities of 13 transgenic rice lines which modified by chitinase gene and other anti-fungal genes. The results showed that the resistances of all transgenic rice lines were higher than their mothers. There were high resistant transgenic lines in which derived from different resistant mothers and modified by single antifungual gene or multiple antifungal genes. The disease-index variation coefficients of transgenic rice lines were 21.93-69.32, wider than the non-transgenic ones, 14.37-47.00. It indicated that resistance of the transgenic rice changed more easily. The analysis of activity of chitinases indicated that the chitinase activities of transgenic rice were higher than their mothers, except one line. But there were no close relationship between resistance and the enzyme activity in transgenic rice lines.