Abstract: In the plainfield of Fuzhou area, the population density is very high but the cultivable land is limited, and the resources of sunshine and heat energy are very wealthy. According to our research data from rice fields the extension of multiple cropping and triple cropping system annually not only can get high economical and effective production, but also can improve the physical and chemical character of soil and increase soil fertility. The productivity of triple cropping system is higher than that of double cropping system,Because of increasing soil organic matter content though the nutrient has been taken away,the soil fertility is not depleting.The triple cropping system of wheat-rice-rice has higherproductivity. Under the condition of increasing fertilizers to crops, plantation of wheat does notdamage rice.