Abstract: Aquatic-chemistry of the lakes including Poyang Lake, Niushanhu Lake, Liangzihu Lake, East Tangsunhu Lake, Longganhu Lake and Huanghu Lake were analyzed from Nov., 1996 to Nov., 1998. On the bases of water quality mornitoring, the seasonal dynamics of main water quality indices (such as transparency, pH, total-nitrogen, total-phosphorus, ammonia nitrogen and nitrate-nitrogen, etc.) and variance analysis of those indices were determined out. The results showed that the difference of the some indices among several lakes with different exploitation models was quite significant except hardness, alkalinity and T-P. The differences of some indices among seasons were also quite significant except hardness, alkalinity, Ca, Mg and T-P. It is implied that the seasonal dynamics at these lakes were quite unstable.