Abstract: In order to increase the yield for mechanical transplanting rice and economic efficiency, field experiment of simulating empty hills was conducted to investigate the effects of empty hills on grain yield in rice. The results showed that rice yield decreased with the increase of missing plants rate, grain yield losses varied from 2.5% to 6.3%, and yield decrease reached significant level when empty hill percentage was above 10% under five empty hill levels including 0% (CK), 5%, 10%, 15%, and 20%. The tillering ability of plants around missing plants enhanced and the decline of percentage of productive tillers was not obvious, increasing the effective panicles and yield of single hill, which could compensate for partial losses of grain yield but not all the losses were brought by missing plants. Meanwhile, total number of grains per panicle, number of filled grain, and 1000-grain weight reduced with increasing of missing plant rates accordingly. Therefore, the rate of empty hills of mechanical transplanting rice would be controlled under 5% and artificial filling the vacancy due to lack of plants in the field should be appropriately adopted to achieve the goal of increasing yield and efficiency when the rate of empty hills was more than 10%.