Abstract: Fault-block and lithologic reservoirs dominate the L1 segment in Weixi'nan depression and have significant different reservoir characteristics and extremely complex water-oil relationships in different domain and different depth. A statistical analysis of 56 reservoirs in L1 segment with separate oil-water systems shows good statistical laws. The statistical data of oil properties shows that there is a better correlation between underground oil viscosity and ground oil properties, and based on it, an empirical formula is obtained which can be used for viscosity prediction of L1 member. Productivity research indicates that sedimentary microfacies, porosity, permeability, oil viscosity and well bore temperature can directly or indirectly affect productivity of L1 segment, and regression relations between different factors and productivity are better which can be used for predicting productivity.