Abstract: At present,all the productivity evaluating methods are only used for gas well.In order to know the potential of the whole reservoir it is very necessary to evaluate the capacity of the whole gas reservoir.This article starts from the basic filtering flow equation,then analyses the gas well deliverability evaluating theory,and finally finds out three capacity evaluating approaches for the gas reservoir.Afterwards,taking the east Jingbian Paleozoic buried platform gas reservoir as an example above mentioned three methods were used to analyze its productivity respectively.In the end,how to evaluate the productivity of newly drilling well was explained based on the method presented in this paper.