To enhance the efficiency of revealing and refining an experts knowledge, the Experts Diagram approach is proposed. The Experts Diagram proposed in this paper is specifically designed for rule-based consulting systems. Using the Experts Diagram approach, the knowledge acquisition system LIFT is developed, which transforms the Experts Diagram automatically to rules in the syntax of the shell SKI 2 that is developed for tax consulting-purposes. For the transformation, either the conclusion-directed approach or the condition-directed approach can be applied. The role of LIFT can be generalized to some extent to adapt to the changes in the Experts Diagram and target shells. According to our experience in the acquisition of Korean corporate tax knowledge, experts could reveal their knowledge effectively using the Experts Diagram after a short period of training. Thus the rules could be generated automatically by LIFT without the aid of knowledge engineers.