Abstract: Lycoris haywardii is a natural hybrids of Lycoris Herb，which is very scarce in nature. It has a low reproductive rate of natural bulb separation and seedling propagation with a long breeding cycle. Effects of plant regulators on the bulb growth and endogenous hormone content of Lycoris haywardii were studied through treated the bulbs with NAA and 6-BA before the leaves emergence， which might provide some theoretical basis and technical support for the development of the Lycoris haywardii industrialization. The experimental data was analyzed by ANOVA and correlation analysis. The results showed that the diameter of bulbs was increased with the treatment of 1 mg·L-1 NAA or 5 mg·L-1 6-BA. Furthermore， NAA was significantly correlated with the increase of the propagation coefficient of bulbs as well. There was significant difference in the endogenous IAA content between the treated group and control group， which showed that IAA was probably one of the key factors of endogenous hormone regulating the bulb growth of Lycoris haywardii.

Key words: plant regulators, endogenous hormone, bulbs growth, Lycoris haywardii