Catharanthus roseus belongs to perennial herbaccous plant and is one kind of subshrub of the Catharanthus in Apocynaceae. There have been more than 100 kinds of alkaloids found in C. roseus, including vindoline, catharanthine and vinblastine. Due to the anti-cancer activity of these alkaloids, this plant has been widely cultivated around the world for the production of vinblastine. How to regulate environmental factors to improve alkaloid contents is the focus of cultivation of C. roseus. During whole the cycle of plants, the limited resource will be trade-off and allocated among vegetative, sexual and asexual reproductions, resulting in different life cycle forms, in order to obtain the most efficiency of survive. Primary and secondary metabolisms displayed different characterisitics accordingly. The effects of partially harvesting on transition of plant life cycle forms of C. roseus and its alkaloid variations according to the theory of plant life cycle form were investigated in order to improve vinblastine and other alkaloid productions. The qualitative and quantitative classification results using the method of primary component analysis (PCA) of harvested C. roseus seedlings revealed that controlled surroundings were suitable to growth and belonged to excellent habitat (E) of C. roseus with the form of V0.2847S0.6684C0.0469, called as SV form. Partially harvesting of seedlings was observed to change the life cycle forms to V0.2847S0.6684C0.0469, belonging to SC form. Coordinated alkaloid contents were investigated and the results showed that vindoline, catharanthine and vinblastine contents was elevated significantly (p<0.05) by treatment. These results showed that partially harvest exibited marked effects on plant life cycle forms and alkaloid metabolisms.