This document presents data from 123 U.S. and Canadian research libraries that were members of the Association of Research Libraries (ARL) during the 2000-01 fiscal year. Since 1987-88, the number of preservation programs managed by a preservation administrator has grown irregularly from 66 to around 80 in more recent years. A fluctuating growth in preservation expenditures and staffing across the ARL membership accompanied this development. Preservation expenditures for ARL's 113 reporting member libraries were $92,276,777 in 2000-01, indicating a slow, irregular increase in expenditures for preservation since 1991-92. Total preservation staff increased to just above 1,800 full-time equivalents (FTEs) in 2000-01, the second time staffing has been over 1,800 FTEs since the survey's revision in 1996-97. Among the types of conservation treatment, Level 1 and 2 decreased slightly, while Level 3 dropped sharply, to its lowest level since 1990-91. Microfilming activity decreased to 62,039 bound volumes; the only time it has been lower since the first "ARL Preservation Statistics" in 1988-89. External funding for preservation activities was $5,579,319, representing almost a $2 million decrease from 1999-2000. Analysis of core data for all reporting libraries is provided in the "Introduction" for the areas of organizational structure, personnel, expenditures, conservation treatment, and preservation reformatting. The data contained in the "Library Data Tables" that follow are descriptive indices of preservation activities in research libraries, including preservation staffs, expenditures, and productivity. A copy of the ARL preservation statistics questionnaire and instructions, as well as footnotes to the statistics, are included. An appendix lists ARL member libraries. (MES)