Eastern China oil fields are usually characterized by considerable faults and high reservoir heterogeneity. Traditionally, the calculation of reserves and acquisition of reservoir parameters often depend on core data of some wells. So, the heterogeneity of an oil field will be concealed. In order to reveal all the geological characteristics of highheterogeneous reservoirs to the best of the authors' ablity and make a fundamental evaluation of such reservoirs, with the Zaoyuan oil field as an example, a full study and description have been made of the geological features of the heterogeneous fault block oil fields, reserves parameters have been exactly determined through divid ing the field into rational calculation units and using core logging data, and the m ethods, flow and key techniques of reserves calculation of these kinds of oil fields have been studies.