Liaoning is the birthplace of japonica hybrid rice. Under the premise of retaining the original advantages,Liaoning Province has carried out continuous germplasm resources innovation, bred high-quality sterile lines represented by 99A, Liao 105A, L6A and Jing 65A, and gradually formed a mechanized seed production technology system. The outcrossing seed setting was gradually improved, and the large area seed production was stable to 2 625kg/ha. The new japonica hybrid rice combination has been widely used.