To elucidate the influence of rape straw returning on soil reducibility and to understand its effects on rice growth and yield in rape-rice rotation system, 3 years field experiment with 8 treatments of straw incorporation carried out at Mianyang Sichuan Province of China. Results showed that the lowest RC Eh value founded at 14-18 d after rice planting; With the increasing of rape straw incorporation, the amount of root (number, weight and length) and root bleeding intensity both increased significantly during 27-32 d after rice planting; 0-20 d are the fast decomposing period of rape straw in rice field. At 10-22 d after rice planting, there is negative correlation between rice root growth and soil reducibility and a negative correlation between rice root and straw incorporation. Oil seed rape straw returning into soil, either by mulching or by ploughing, make the soil more reducible with lower Eh and higher content of reducing material, Fe 2+ and hinder the growth of rice root with lower amount (length, weight and number) and bleeding density during this period. Comparing with other straw returning methods, straw returning by ploughing method with the rape straw of 3.0 t/hm 2 is more suitable in rice-rape rotation farms where is convenient for mechanical operation. 1 INTRODUCTION Straw is a comparatively abundant resources in China, producing 0.79 billion tons of straw annually (Zou et al., 2016). Considering from effective use of straw resources, more Abbreviation: RC Eh , Daily changes of soil redox potential; RC Fe , Daily changes of Fe2+ in soil; RC RBI , Daily changes of root bleeding intensity of rice; RC RLT , Daily changes of the total length of rice root; RC RLW , Daily changes of the length of white rice root; RC RNT , Daily changes of the total number of rice root; RC RNW , Daily changes of the number of white rice root; RC RQT , Daily changes of the total weight of rice root; RC RRM , Daily changes of total reduction substances in soil.