Abstract: Gibberellic acid (GA) could effectively delay plant senescence and improve the feed quality of rice (Oryza sativa) straw, but studies have shown that rice plants with applied GA are slow to ripen. In order to investigate the nonstructural carbohydrates (NSC) content of rice straw at different harvest times after GA application, four different rice varieties have been studied: Liangyoupeijiu (late maturing medium indica), Wuyujing 3 (late maturing medium japonica), Nanjing 44 (early maturing late japonica), and Nanjing 46 (medium maturing late japonica). The study investigated three GA application times: 7 days after anthesis (GA-7), 15 days after anthesis (GA-15) and 21 days after anthesis (GA-21). Two harvest times were also set (1: the control grain had reached 80% maturity; 2: 6 days after harvest time 1). The NSC content [including water soluble carbohydrates (WSC) and starch] in different parts of rice straw have been analyzed. The top 3rd internodes of rice plant were used to make freehand cross-sections to observe the starch granule quantities. The results indicate that the NSC content in rice straw is considerable, with japonica scoring higher than indica varieties. The stem is the main storage organ for NSC. WSC content was higher than starch content. At harvest time 1, the optimal GA application time for Liangyoupeijiu was 15 d after anthesis, for Wuyujing 3 21 d after anthesis, and for Nanjing 44 7 d after anthesis. The optimal GA spraying time for Liangyoupeijiu was 21 d after anthesis, 15 d after anthesis for Wuyujing 3, and 21 d after anthesis for Nanjing 44. For Nanjing 46, the optimal GA application time at both harvest times was 15 d after anthesis. Spraying GA during the late growth period could effectively increase the NSC content in rice straw for the indica rice variety Liangyoupeijiu and the medium japonica rice variety Wuyujing 3, but the effects for late maturing japonica varieties Nanjing 44 and Nanjing 46 were not significant.