In this experiment,the maize varieties ’Xianyu 335’ and ’Nongda 364’was chosen as the test materials.1/4,2/4 and 3/4 of leaves were cut off and 1/2 of the spikes were cut off to study effects of changes of source and sink on yield and related characters of maize.The results showed that effect of reducing source was greater than reducing sink on dry grain weight and yield for ’Xianyu 335’.On the contrary,that effect of reducing sink was greater than reducing source on dry grain weight and yield for ’Nongda 364’.