Abstract: At present,differential permeability or coefficient of variation is often used to evaluate series rationality in the process of oilfield development.As for heavy oil reservoir with big fluid properties variance in vertical direction,the only physical parameter,permeability,is difficult to accurately evaluate the series rationality,therefore,the mobility variation degree is chosen.By drawing references from the orenz curve method in the calculation of mobility variation degree,dynamic data of 12 heavy oil reservoirs in Shengli oilfield have been chosen.Through statistics analysis between the flow degree coefficient of variation and interference within the series,relevant formulas and the judgment standard of similar reservoir on the series rationality have been achieved.Through the size of mobility variation degree,series disturbance can be estimated.The method is simple and practical.