Abstract: To explore the effect of transplanting female parent of hybrid rice by machine on seed yield，experiments on seed production of hybrid rice“ Boyou225” were conducted，in which its female parent was transplanted by machine and by hand，at three locations and in two years. Differences in growth dynamics and yield components were investigated between machine- and hand-transplanted female parent populations. Factors affecting the yield of hybrid seeds were analyzed. The results showed that，the number of seedlings per hill，the maximum number of tillers per plant，canopy thickness，the number of productive panicles per plant，the number of filled grain per panicle，seed-setting rate，the estimated production and the actual production were all more in machine-transplanted population than those in handtransplanted population. Filled grain number and the maximum number of tillers were most closely related to the yield of hybrid seeds，respectively，among yield components and among seedling growth indices. Transplanting female parent by machine in hybrid rice seed production，was contributed to an increase in the maximum number of tillers and filled grain number for the parent population，thus improving the yield of hybrid seed.