Using a survey to identify the classification systems employed in Illinois public community college instructional materials centers, this study considered three questions: Was there a trend developing in the use of the Library of Congress (LC) system? What factors influenced this trend? Was this trend more evident in large centers than in small centers? An analysis of the data gathered from 40 of the 47 questionnaires sent to resource center directors revealed the following: (1) 70 percent of the centers used the LC system and 30 percent used the Dewey Decimal Classification (DDC) system; (2) economy, up-to-dateness, and greater flexibility influenced the selection of LC over DDC; (3) browsing capabilities, students' knowledge of the system, inheritance of the system, and the expense of reclassification influenced the selection of DDC over LC; (4) librarians' training in the use of the systems did not influence system selection; and (5) LC was the most prevalent system adopted in all sizes of centers surveyed. This study includes a bibliography and appendices which contain a list of colleges polled, a sample cover letter, and a sample questionnaire. (FM)