We had an experience of blood purification for an infant with oxalosis. For the small child, a living related liver-kidney transplantation was performed. Over the fifty days between transplantations, hemofiltration (HF) and hemodiafiltration (HDF) treatments were performed to remove oxalate from the patient. Some techniques were introduced to maintain safety. Optimum operating conditions were evaluated from an analytical study. At 1hr after the start of the treatment, the values of urea and β₂-microglobulin clearance were 16.9ml/min and 7.0ml/min, respectively, under 20ml/min of blood flow rate, 40ml/min of dialysate flow rate, and 0.28l/hr of filtrate flow rate. The total amount of oxalate removal was 31.2mg during a 7hr and 40min of HDF treatment. An appropriate treatment for infants with oxalosis can be performed with some devices, taking the low flow conditions into account.