BACKGROUND/AIMS: This study was conducted to investigate the effect of alpha-interferon after prednisolone withdrawa] therapy on chronic active hepatitis B with HBeAg. METHODS: Twenty- three CAH patients were recruited at a general hospital in Pohang city from August 1990 to July 1991. Dose of 45mg, 30mg and 15mg of prednisolone were administered to patients for two weeks and two weeks pause, after that three million units of alpha-interferon 2b was injected once a day for the first week, and then the same dose was injected three times per week for eleven weeks. Patients were followed up for side effect and changes in serum ALT, HBsAg and HBsAb, HBeAg and HBeAb, HBV-DNA, DNA-polymerase and peripheral blood smear during and after treatment. RESULTS: Seroconversion rate of twenty three HBeAg positives at 6 months after treatment was 61% and that of HBV-DNA positives was 48% and both seroconversions occurred in 39% of patients. The normalization rate of ALT was 61% after alpha-interferon therapy. However there were no patients who was become negative among HBsAg positives, Serum ALT decreased at four weeks after administering the alpha-interferon, and a continued decrease was obsered during therapy. However, a gradual increasing of ALT happened after finishing therapy and reached the average level of 79.6IU/L in the eighth week after theropy. The incidence of side effects after alpha-interferon therapy was not serious enough to withdraw therapy, They reported mild symptomes such as, anorexia(69.6%), myalgia(56.5%), fever(52.2%), fatigue(34.8%), arthralgia (26%), nausea(26%), mild hair loss(17.4%) and headache(13%). CONCLUSIONS: It was shown that alpha-interferon with prednisolone withdrawal therapy was effective in patients with CAH in terms of seroconversion of HBeAg and decreasing activity of HBV-DNA and normalization of ALT value.