Abstract: Situated in the southern steep slope zone of Biyang depression,Bi-304 block is of the characteristics of complex mode pore structure,big capillary resistance,high content of montmorillonite and serious homogeneity,which makes it hard to make breakthrough in productivity evaluation such as early testing and fracturing production.Therefore,starting from core observation,in combination with oil-bearing characteristics and corresponding electric response characteristics,classification standards of the reservoirs in this area has been established.From the characteristics of oil-bearing,lithology and physical properties,four types have been classified.The application in type-I reserves achieves good effect in productivity breakthrough.