GENERAL PRISON STATISTICS ARE INCLUDED IN THE BACKGROUND DISCUSSION OF THE SWEDISH PRISON SYSTEM, WHICH IS CHARACTERIZED BY A LIBERAL, HUMANE APPROACH TO INMATE TREATMENT. SCIENTIFIC MEASUREMENTS OF THE EFFECTS OF THE PRISON SYSTEM ON OFFENDERS' LIVES DURING AND AFTER INCARCERATION ARE ACKNOWLEDGED BY THE AUTHOR TO BE WEAK IF NOT ABSENT IN SWEDEN. ALTHOUGH IT IS INDICATED THAT LIMITED AMOUNTS OF MONEY ARE SPENT ON PRISON RESEARCH, SOME SIGNIFICANT RESEARCH STUDIES ARE DISCUSSED. THE LARGEST SINGLE CATEGORY OF STUDIES CONSISTS OF VARIOUS SURVEYS OF THE PRISON POPULATION OR SEGMENTS OF IT. AMONG THE RESEARCH STUDIES TREATED IN THE PAPER ARE THE FOLLOWING: THE INCIDENCE OF DRUG MISUSE AMONG THE NEW ADMISSIONS TO PRISONS AND ITS CORRELATE WITH SOCIAL, PERSONAL, AND CRIMINAL HISTORY; THE SIGNIFICANCE OF THE KNOWLEDGE OF CRIMINAL ARGOT AMONG GIRLS IN A LARGE STATE INSTITUTION FOR JUVENILES; THE EFFECTS OF DIFFERENT TYPES OF IMPRISONMENT; AND A STUDY OF THE RELATIVE EFFECTIVENESS OF PRISON AND NON-IMPRISONMENT ON OFFENDERS....RCB