In order to provide the scientific basis for application and promotion of Cuikang foliar fertilizer in major rice producing areas of the middle-lower Yangtze River Basin, the field application trials were conducted to the single cropping rice and double cropping late rice in Bajiawan village, Qinghuapu town, Ningxiang County, Hunan province in 2010. The results showed that in comparison with the control, spraying Cuikang foliar fertilizer at different period all can improve spikelet number and seed-set rate, the highest increase range of them in single cropping rice were 11.5% and 12.4% respec...