On the base of high resolution sequence stratigraphic research of the purpose layer in study area, writers analysis the quality heterogeneity in underwater distributary channel reservoirs. Applicating different base level cycles of sedimentary analysis and characterization of reservoir heterogeneity of the quality of core test, statistical data analysis, writers pointed out that base level cycle factors on different levels of underwater distributary channel in the main reservoir quality heterogeneity difference: single underwater distributary channel and single phase composite underwater distributary channel reservoirs quality heterogeneity of positive rhythm changes, multi phase composite underwater distributary channel reservoirs quality heterogeneity of irregulartrend, multi level base level cycle sand accompanied accommodation changes caused by the change of depositional environment effect the reservoirs heterogeneity of underwater distributary.