Ten-year trend data reveal that rates for juvenile arrests and new referrals from 1974 to 1983 have declined by 41.2 and 28.3 percent, respectively. As of December 31, 1983, a total of 67,236 juvenile cases were under supervision by probation departments. Of these, 87.9 percent were on formal supervision bases, 10.4 percent on informal supervision basis. Included are 41 charts and 24 tables giving data on juvenile justice trends, juvenile arrests, new referral and re-referral dispositions, juvenile arrest trends, new referrals and re-referrals to the probation department and juvenile court, commitments to California Youth Authority, and juvenile population in county detention facilities.