Since the reform and the opening-up policy was carried out in 1978,the rural residents' income have been grown steadily.But the speed of rural residents' income growth is obviously different in different regions,even in the same region.This paper analyzed the difference of per capital net income of rural households(PCNIRH) disparity in the Yangtze River Delta by using absolute discrepancy index,relative discrepancy index,inverted-U shape curve hypothesis and convergence method from 1978 to 2004.