Abstract: With Catharanthus roseus, we used perlite as culture substrate to study the biomass and secondary metabolism. Three main alkaloids in plants were decreased with reduced levels of nitrogen. The level of exogenous nitrate on vindoline and Catharanthine in C.roseus was with more significant accumulation in the leaves at different leaf positions, but with little effect on the accumulation of vinblastine. In high nitrogen condition, the plant synthesis and accumulation were at higher levels of free amino acids, which may provide the skeleton and promote the improvement of alkaloids in the partial synthesis. The content of sucrose in different position leaves was increased slowly with the increase of age. The content of sucrose in leaf at higher nitrogen level was significantly higher than that at normal nitrogen level. This research provide the reference basis that the important medicinal value for improving the content of alkaloid.

Key words: Catharanthus roseus, nitrate nitrogen, alkaloid, secondary metabolism