PURPOSE: This study was designed to assess the effects of cyclic parenteral nutrition(CP) on parenteral nutrition induced liver diseases. METHODS: Before and after CP, data were collected on diagnosis, age, duration of parenteral nutrition, macronutrients and biochemical parameters. Initially parenteral nutrition was cycled off for 1-2 hours and the off-time was advanced by 0.5-1 hour daily over 1 week. Blood and urine glucose were monitored during procedure. RESULTS: Data on 6 sets of CP in 4 patients, among whom 2 patients had undertaken CP 2 times, respectively, were analyzed. The mean age was approximately 4 months, ranging from 2 to 11 months. Underlying diseases were as follows : 2 cases of microvillous inclusion disease, 1 case of protracted diarrhea of infancy and 1 case of feeding intolerance. The mean duration of parenteral nutrition before CP were 38.6 days, and that of CP was 41.6 days. During CP, the mean total caloric intake of each patient was 107kcal/kg/day, and the mean weight gain was 6.0g/kg/day. After CP, the biochemical parameters changed as follows : bilirubin was decreased in 4 cases, not changed in 1 case but increased in 1 case who had sepsis during CP period; the level of ALT was decreased in 2 cases but increased in 2 cases and not changed in 2 cases. Overall, CP was tolerated well although 3 cases had hypoglycemia(serum glucose concentration less than 40mg/dL) at the initial CP period. CONCLUSION: CP has potential beneficial metabolic effects on total parenteral nutrition induced cholestasis with minimal complications.