Abstract: Abstract: There is great meaning to research the effect of oil-seed rape straw incorporation on reducing material change in soil and the growth of rice root, with the objective of founding reasonable filed management for straw incorporation technology, by investigating the reason why rice growth was slow under the condition that oil-seed rape straw was retuned into the rice field. By field experiment and simulation experiment, this paper analyzed the dynamic change of the potential of oxidation-reduction (EH), and the reducing material and Fe2+ content in rice field, and investigated the dynamic change of root number, root weight, root volume, root length and root bleeding intensity. The results showed that: 1) The daily mean variation of potential of oxidation-reduction (RCEH) had a trend of ascending after descending, and the lowest value was found after 14-18 d of rice planting, while the values of daily mean variation of reducing material (RCRRM) and Fe2+ (RCFe) performed a trend of ascending and then descending, with the highest RCRRM value after 10-14 d of rice planting and the highest RCFe value after 14-22 d of rice planting. 2) Under the condition that oil-seed rape straw was incorporated into the rice field, with the increasing of oil-seed rape straw incorporation amount, rice number, rice weight, rice volume, rice length, white root amount and root bleeding intensity increased significantly. Compared with straw mulching method, the affecting period of straw incorporation on the daily mean variation of root bleeding intensity (RCRBI) under straw ploughing method was longer; the slow grow period of rice root system extended by 4 days under straw ploughing method. 3) After 10-22 d of rice planting, there was negative correlation between rice root growth (daily mean variation of (RCRNT, RCRQT, RCRLT and RCRVT) and soil environment (RCEH value, RCRRM value and RCFe value) and negative correlation between rice root and straw incorporation amount; after 27-32 d of rice planting, there was a positive correlation between rice root and soil environment and also a positive correlation between rice root and straw incorporation amount. As the time went on, the impacts of straw incorporation on root growth of rice became less and less, and after 27-32 d of rice planting, its impacts decreased significantly. The conclusions are as follows: Under the condition that oil-seed rape straw is incorporated into the rice field, with the increase of straw incorporation amount, the Eh decreases significantly, while the reducing material and Fe2+ content increase significantly; rice root (number, weight, volume and length), white root (number and length) and root bleeding intensity decrease significantly during seedling stage of rice. As the time goes on, the impacts of straw incorporation on root growth of rice become less. The affecting period of straw incorporation on soil environment and root growth with straw ploughing method is longer than straw mulching method, and incorporating oil-seed rape straw into soil with ploughing method is better than straw mulching method for rice yield. Under the condition that is feasible to use agricultural machine, ploughing method is a better method to return oil-seed rape straw into field.