Abstract: With field test, overturning Astragalus sinicus into paddy fields was conducted to study its effects on crop growth of watermelon-rice rotation.The results showed that there were no significant differences in watermelon yields resulting of Astragalus sinicus plus either normal fertilization or lessening 20%-40% chemical fertilizer while compared with normal fertilization.Nevertheless, overturning Astragalus sinicus combined fertilization treatments improved the sugar content of watermelon, particularly with a significant increase of 9.6%¹4.7%for central sugar (P<0.05) .For rice after watermelon crop, overturning Astragalus sinicus significantly improved rice growth during the tillering stage and increased the number of grains per tassel in mature stage.Likewise, the yield of rice grain was significantly increased by 7.6%-17.0%, the most significant result found from the treatment of overturning Astragalus sinicus 45000 kg hm-2+100% of chemical fertilizer (HZ+100% H) .Overturning Astragalus sinicus not only increased the quality of watermelon in central and marginal sugar content, but also improved the yield of rice after watermelon, which suggested a continuous aftereffect.