Abstract: To study the growth dynamic of Maca (Lepidum meyenii), the research was conducted. After seedling transplanting, the plant samples were selected through a random sampling method to measure the growth rate of each organ about once a month. The results showed that: Maca rapidly grew from August to November. And the growth trends of the leaves’ fresh and dry weight were like an inverse ‘V’ , however, the trends of the roots’ fresh and dry weight were like a ‘S’. The leaves’ number and maximum length, as well as their fresh and dry weight, reached their maximum in the middle of November. And the roots’ length and diameter, as well as their fresh and dry weigh, reached their maximum in January of the following year. The ratios of both leaves’ fresh weight and dry weight according to whole weight tended to decrease with the growth stages advance, while that of the roots’ were opposite. There was a downtrend result could be observed for the proportion of fresh weight to dry weight of Maca, while the trend of ratio of root to shoot was upwards with the growth stages advance. When harvested in January of the following year, the yield of roots was the highest.