【Objective】Crop rotation of rice and winter wheat is a common farming practice in areas of the middle and lower reaches of the Yangtze River. However, the paddy soils under such a cropping system are always heavy in texture, and tend to bring about waterlogging stress to the crop of winter wheat during its growing season under monsoon climate of winter wheat, thus inducing severe yield losses or loss of the whole crop. It is, therefore, essential to seek for a low cost and environment friendly method to alleviate yield losses caused by waterlogging stress for the sake of local food security. Biochar is an effective soil amendment and can be used to reduce soil hardening and enhance soil organic carbon sequestration. Nowadays, researches have has been carried out on application of biochar in areas under the crop rotation system in the middle and lower reaches of the Yangtze River. However, little has been reported on quantitative evaluation of the effect of biochar alleviating waterlogging stress of winter wheat in South China. 【Method】Therefore, in the present study, soil column and plot experiments were conducted to investigate effects of application of biochar derived from rice straw in paddy fields under the rotation system on growth of winter wheat at its early stage, in an attempt to obtain a preliminary evaluation of the prospects of biochar application to alleviate waterlogging stress. Effects of biochar application varying in rate on soil bulk density and soil water content at different depths were evaluated through the soil column experiment, and its effects on wheat germination and wheat growth at early stage were through the plot experiment.【Result】Results show that biochar application significantly reduced bulk density of the soil. When biochar was applied at a rate of 10 and 40 t hm^-2, soil bulk density was lowered by 7.4% and 11.4%, respectively, compared with CK (the treatment with no biochar applied). Dynamics of the soil in water content varied with soil depth. biochar application facilitated soil water percolation, thus alleviating the risk of waterlogging. Specifically, in the soil applied with biochar, soil water content at 20 cm in depth dropped rapidly after a simulated rainfall event compared with that in CK. The changes in physical properties of the soil applied with biochar indicated that drainage conditions of the soil were improved, favoring growth of winter wheat. In addition, compared with CK, biochar application at a rate of 10 t hm^-2 (BC) accelerated seed germination and promoted wheat growth at its early stage. Samples of winter wheat were collected on D90 after sowing for analysis of plant height, taproot length and chlorophyll relative content (SPAD value) of the new fully expanded leaf. It was found that they were all significantly higher in the treatments applied with biochar than in CK (p<0.05). The findings fully demonstrate that biochar application is beneficial to wheat growth at its early stage. However, its effects on dry matter weight of root, stem and leaf were not significant. In terms of characteristics of the root system, the plants in the biochar treatments had longer taproot than those did in CK, but did not differ much in total root length and total root area, which may be explained by the heavy texture of the soil CK. In such soils, the plant can not have its taproot go deep and for compensation have more lateral roots developed for water and nutrient absorption. 【Conclusion】On the whole, biochar application can significantly improve drainage of the soil under crop rotation and benefit growth of the wheat at its early stage. All the findings listed above demonstrate that biochar application has the potential to alleviate waterlogging stress. However, further efforts should be made to study effects of biochar application on physiology and yield of winter wheat subjected to waterlogging so as to validate the hypothesis.