In 1980, California statistics show that 63 percent of arrests for dealing marijuana were whites, which was close to the percentage of whites in the State's population between 15 and 39 years old (69 percent). By 1986, the marijuana felony arrests were overwhelmingly of Latinos and blacks. From 1980 to 1986, marijuana felony arrests of whites declined by 42 percent, to under 7,500; arrests of blacks increased 5 percent; and Latino marijuana felony arrests rose 170 percent, to over 7,000 in 1986. This enormous shift in the racial and ethnic composition of marijuana-dealing arrests is not due to some sudden shift of enforcement policies, or improved recording of Latino status in police arrest reports. The diametrically opposed arrest trends of brown and black minorities versus whites reflect actual market conditions as the police encounter and/or create them. Theories regarding the increased usage and arrests of minorities include (1) usage and arrests increased in response to reducing the penalty for possession of 1 ounce or less of marijuana, (2) drug dealing provided upward mobility for minorities and the risk was accepted, and (3) whites felt the increased risk of arrest and this served as a deterrent. The data do show that marijuana law enforcement in California shifted from the user to the dealer. 10 notes and 15 references.