General trends in penal code offenses in Japan show a sharp rise from 1946 to 1948, a decrease to 1953, an increase culminating in 1964 (exceeding the 1948 peak), a slight 2-year decrease, followed by a third period of acceleration which peaked in 1970; a decrease from 1971-74 has been followed by a gradual increase to a 1980 total of 1,812,755 offenses, second only to the 1970 peak of 1,932,401. The 1980 figure represents 1,355,974 nontraffic penal code offenses, compared to a high of 1,599,968 in 1948. Trends are discussed for the following specific crimes: those committed by violent gangster groups, violent crime committed by youthful extremists, crimes committed by public officials, pollution offenses, public election law violations, traffic offenses, crimes by female offenders, crimes committed by foreigners, and crimes committed by Japanese in foreign countries. Drug offenses and mentally disturbed offenders are also considered. The discussion of research on sentencing through the use of computerized criminal records considers trends in imprisonment for heinous crimes, violent crimes, property offenses, drug offenses, and negligence offenses. Trends in fines are examined as well. Limited tabular and graphic data are provided.