This study explores the effects of six weeks basketball systematic exercise on female undergraduate student athletes' serum nitric oxide and nitric oxide synthase leve1.The changes of NO and NOS level in female players serum are observed and the result indicates that serum NO content and NOS activity of exercise groups are remarkably higher than those of the control groups.Through systematic exercise training,the activity of NOS is reinforced and the synthesis of NO is increased.These have important meaning...