To study the effects of different reagents on seedling quality of machine-transplanted early rice, the authors evaluated the effects by soaking seeds, mixing seeds and spraying seedlings. The seedling quality evaluation revealed that KH2PO3 was the best treatment during soaking seeds. Meanwhile, Na2HPO4, KH2PO3 and CaCl2 were antagonistic each other. Gaoqiao was the best one after mixing seeds and the performance of all the three treatments were better than the control. It was distinct that Gaoqiao was quite good for growing root ability. The mixture of Na2HPO4, KH2PO3 and CaCl2 was the best treatment if spraying seedlings. Generally speaking, commercial reagents used for mixing seeds were better than inorganic chemicals used for soaking seeds. The effects of KH2PO3 were close to those of commercial reagent, and the effects by soaking seeds or mixing seeds were better than those by spraying seedlings.