THIS PRELIMINARY REPORT DESCRIBES THAT PHASE OF THE UCLA MEXICAN-AMERICAN STUDY PROJECT WHICH CONCERNS THE IMMIGRATION PROCESS OF MEXICANS TO THE UNITED STATES. STATISTICS ARE PRESENTED ABOUT--(1) THE VOLUME OF IMMIGRATION OVER THE YEARS, (2) THE SOCIO-ECONOMIC CHARACTERISTICS OF IMMIGRATING MEXICANS, (3) THE GEOGRAPHIC DISTRIBUTION OF MIGRANTS AFTER IMMIGRATION, (4) THE REASONS FOR THEIR MIGRATION, (5) THE DIFFERENCES BETWEEN PERMANENT AND TEMPORARY MIGRATING MEXICANS, AND (6) THE COMPARABLE ASPECTS BETWEEN MEXICAN AND CANADIAN IMMIGRATION. THE DISTINCTIVE FEATURES OF MEXICAN IMMIGRATION ARE DIFFERENTIATED FROM EUROPEAN IMMIGRATION, INCLUDING MEXICO'S ATTITUDE TOWARD EMMIGRATION, THE SELECTIVE PROCESSES INVOLVED IN MEXICAN IMMIGRATION, THE ECONOMIC FORCES THAT INFLUENCE MIGRATION, AND THE FUTURE OF MEXICAN IMMIGRATION. THE APPENDIX CONTAINS STATISTICAL CHARTS AND AN EXPLANATION OF THE IMMIGRATION AND NATURALIZATION LAWS. THIS REPORT IS AVAILABLE FOR $3.00 FROM THE MEXICAN-AMERICAN STUDY PROJECT, UNIVERSITY OF CALIFORNIA, GRADUATE SCHOOL OF BUSINESS ADMINISTRATION, LOS ANGELES, CALIFORNIA 90024. (JH)