Abstract: The seasonal changes of N, P and K contents in the soil of an Aneurolepidium chinensis grassland were relatively high in the initial growth stage, relatively low in the peak growth stage from June to August and went up again at the end of the growth season.The N, P and K concentrations in the aboveground tissues were 3.6, 2.9 and 2.8 times, respectively, of those in the below ground. The seasonal changes of these three elements assumed a singlepeaked curve. They gradually increased at the initial growth stage, maximized in August, and then gradually declined. The concentrations of the three elements tended to increase during the growth season, and an apparent gradual accumulation of them in the growing roots was found.An analysis of the seasonal dynamics of N, P and K in the plant-soil system revealed that the proportions of them in different compartments tended to reach a constant with time. In the steady state, the N, P and K contents decreased 21.23, 5.14 and 2.99%, respectively, in comparison with the initial concentrations. In other states, the N, P and K concentrations tended to increase in all the compartments, especially in the litter and roots, which suggested that litter and dead roots are the major nutrient storage pools.