在池塘鱼种越冬中，鲢鳙鱼种冬后体重损失率分别为1.97%和5.02%，而在东湖网箱中则为3.47%和1.69%。室内水族箱鲢鳙鱼种在5--12℃下，经过107天饥饿，体重损失率分别为25.08%和25.00%。在室外水泥池试验中，鲢鳙鱼种经过116天饥饿，体重损失率分别为27.84%和24.45%（C池），投喂人工饲料的鲢鳙鱼种体重损失率分别为15.21%和9.20%（D池），而肥水池中则分别为2.93%和4.15%（E池）。池塘和培肥水泥池中鲢鳙鱼鱼种体重损失率明显低于C池鲢鳙鱼种，东湖网箱中鲢鳙鱼种也明显低于室内水族箱，是由于鲢鳙鱼种的冬季摄食作用。冬后池塘和网箱鲢鱼种体内脂肪和蛋白含量明显高于饥饿鲢鳙鱼种，而水分明显低于后者；以及池塘和风箱鲢鳙鱼种血液中的红细胞数、血红蛋白和血浆总蛋白含量高于饥饿鲢鳙鱼种，也反映也冬季鲢鳙鱼种的摄食作用。鲢鳙鱼种的摄食强度受水温和浮游生物的影响，实验期间鲢鳙鱼种明显摄食与武汉地区冬季水温及浮游生物量相对较高有关。解剖观察也发现鲢鳙鱼种肠道内含物较多，充塞度多在2-4级；肠系膜上脂肪明显，多数在1-5级。越冬鱼种密度过高对其体质有不利影响，高密度池（B）中鲢鳙鱼种冬后体重损失率分别是低密度池（A）的2.21倍和1.61倍，这在生化成分含量上亦有反映：A池鱼体脂肪及蛋白含量高于B池，而水分含量则低于B池。冬季浮游生物种类少，但其生物量可由培肥增高，培肥池中浮游生物量平均为18.65±6.81mg/L。鲢鳙鱼种能摄食人工饲料，但摄食饲料鱼种体重损失率明显高于摄食浮游生物鱼种，原因可能与鲢鳙鱼种对食物的喜食程度有关。因此，在武汉地区可通过降低越冬鱼种的放养密度和培肥水质达到降低鱼种体竽损失率，提高越冬鱼种体质和成活率的目的。During the overwinter periods, the weight loss rates (WLR) of silver carp (Hypophthalmichthys molitrix) fingerings were 1.97% in pond, and 3.47% in cages in Lake Donghu; the WLRs of bighead carp (Aristichthys nobilis) fingerlings were 5.02% in pond, and 1.69% in cages in lake Donghu. After 107 days of starvation in indoor aquaria, the WLRs of silver carp and bighead carp finderlings were 25.08% and 25.00%, respectively. In the experiments in concrete pools, the WLRs of silver carp fingerlings were 27.84% in pool C (starved fingerlings), 15.21% in pool D (fingerlings fed artifitial diet), and 2.93% in pool E (fingerlings fed plankton); the WLRs of bighead carp fingerlings were 24.45% in pool C, 9.20% in pool D, and 4.15% in pool E. The fact that the WlRs in ponds and in pool E were much lower than those in pool C, and the WLRs in cages in Lake Donghu were also much lower than those in indoor aquaria, may be caused by the feeding of silver carp and bighead carp fingerings during winter. The postwinter fat and protein contents in muscle and liver, the red cell number, haemoglobin and plasma total protein in blood in the pond and cages were higher than those in pool C after winter. This may also reflect the effect of feeding of silver carp and bighead carp fingerlings. The intensity of feeding is affected by the temperature and biomass of plankton in winter, and was relatively high in the experimental periods. The body quality of fingerings decreased under the condition of high stocking density, The WLRs of silver carp and bighead carp in pond B were 2.21 and 1.61 times higher than those in pond A; the fat and protein content in pond B were lower, and the water content was higher than those in pond A. The number of species of plankton in winter was small, but the biomass can be high by applying manure in pond. The average biomass of plankton in fertilized pool E was 18.65±6.81mg/L. The fingerlings of silver carp and bighead carp can consume artificial diet (ingredients: wheat bran (64%), ground bean (30%), fish meal (5%), and additive (1%).), but the body condition of fish fed artificial diet was lower than that of fish fed plankton. This may be related to the food selectivity of silver carp and bighead carp fingerlings. Therefore, winter loss in body condition may be reduced by decreasing the stocking density of fingerlings and fertilizing in the ponds.