Through fixed field experiment and determinations of soil moisture,the field water utilization efficiency of wheat and rape seeds was discussed under no tillage and straw mulching.The result indicated that the increasing effects of soil water content and the decreasing of water evaporation which caused by rice straw mulching were very apparent in the 0-10 cm surface layer of soil, and the effect of straw mulching in the wheat field was better than that of in the rape seeds field.As compared with ck,the soil water storage was increased by 13 560-33 360 m~3·hm~(-2) under no tillage and straw mulching.The water utilization efficiency of wheat and rape seeds was improved by 5.9 %-26.9 %.