Objective To design a new pre-treatment device and to evaluate its efficiency in order to monitor the tritium levels in biological samples.Methods The detection efficiency of tritium was determined with standard tritiated water.Recovery of tritiated water and organically bound tritium (OBT) were detected with high, medium and low activities of standard tritiated water and 3H-TdR (tritiated thymidine), respectively.Comparison of three kinds of biological samples using different pre-treatment devices was shown.Results The standard curve can be used in environmental tritium measurement and the detection efficiency for tritium was 23.3%.When 40.0 g rice with standard HTO or 3H-TdR was pretreated with this device, the average recovery of HTO and OBT was about 95.4% , which showed good reproducibility.The comparison results were similar.Conclusions The pre-treatment device can be used to survey the OBT in environmental biological samples.