Abstract: Objective To compare the high cut-off hemodialysis with high flux hemodialysis for free light chain removal, and to review literatures concerned.Methods A male aged 59 was admitted due to "fatigue more than one year, aggravated two days". He felt fatigue one year ago and was diagnosed as multiple myeloma by bone marrow biopsy and increased free light chain. Then partial remission was achieved by thalidomide, adriamcin and dexamethasone. One week before, he felt weakness and chest pain, then a decrease in hemoglobin and acute renal failure were found, which was considered the recurrence of multiple myeloma. Cyclophosphamide, doxorubicin and dexamethasone chemotherapy was started. When the creatinine up to 611 μmol/L, the hemodialysis treatment began. He received two times high flux hemodialysis (Fresenius FX60) first, then three times high cut-off hemodialysis (HCO2100). Time was four h and ultrafiltration was set at 0.5 kg. Human albumin 10 g was replenished at high flux hemodialysis for 3.5 h. The levels of serum FLCλ were detected by particle enhanced turbidimetric immunoassay, and those of serum albumin by automatic biochemical immunoassay before and after treatment.Results After two times high flux hemodialysis, serum levels of FLCλ were decreased from 45.9 to 36.4 mg/L, and those of albumin changed from 31.9 to 32.7 mg/L respectively. After three times high cut-off hemodialysis, serum levels of FLC λ decreased from 42.3 to 32.1 mg/L, and those of albumin were decreased from 33 to 28 mg/L (10 g albumin was added in each high cut-off hemodialysis).Conclusions We didn't find the superiority of high cut-off hemodialysis over high flux hemodialysis for serum FLC removal in multiple myeloma on renal replacement therapy. During four hours of high cut-off hemodialysis, albumin loss can be effectively prevented by intravenous administration of 10 g albumin.