This paper presents the results of a review of professional compensation systems in a number of major academic libraries which was conducted in order to advance the understanding of librarian compensation and to help libraries choose and develop systems that best promote librarians' interests. The systems of compensation identified during the review are briefly described, including free form, professional ranking, position classification, and mixed. As background to the discussion, the most common industrial compensation systems are reviewed. An outline of professional compensation systems are reviewed. An outline of professional compensation methods, specifically position description, standard job evaluation, generic classification, the career-curve approach, and the individual contribution approach, is also provided. The salary compensation systems represented by libraries contributing information to the study are then discussed in detail, with special attention paid to professional ranking with and without subdivisions and to position classification as in the federal system. Among major issues reviewed are institutional and financial constraints on library compensation systems, the use of merit review procedures, job value, and alternate reward systems. A 9-item reference list is included. (JL)