Using japonica rice varieties Longjing 20 and Longjing 58 as test materials. Two planting methods, sowing in line under water and conventional rice transplanting, will be set up from 2017 to 2018. The effects of sowing in line under water on rice growth and yield, yield components and economic benefits were studied. The results showed that the plant height, ear traits and yield of Longjing 20 and Longjing 58 under sowing in line under water showed a downward trend compared with conventional transplanting. The main reason for the decrease in yield is due to the decrease in grain number per spike, grain formation rate and 1,000-grain weight. From the perspective of economic benefits, the economic benefits of sowing in line under water are higher than that of conventional transplanting. Compared with conventional transplanting, the production cost of sowing in line under water is reduced by 70%, the output value per hectare is reduced by 324 yuan, the cost is reduced by 4,260 yuan, and the net benefit is increased by 3,936 yuan.