Abstract: The relations were studied between lily bullet formation and physiological age of scale , cutting ways , phosphorus (P) and potassium (K) concentrations in medium , anatomy and physiological changes. The results showed that middle layer scale crosscut into 6 sections had the highest propagation coefficient . Compared with others sections , the scale base had the highest propagation coefficient and the earliest generation of bullet , propagation coefficient decreased from the base to top of scale. Scale color and shape changed distinctly along with milky white →pale yellow →pale purple →green purple →scale withering and bullet growing. Chlorophyll content of scale increased , but starch and sugar contents of scale decreased. The suitable increases of phosphorus and potassium concentrations in medium increased the quantity and quality of bullet .

Key words: Lily, Tissue culture, Explant, Cutting way, Bullet