Purpose: For the purpose of using Re-188 as a therapeutic radionuclide, we performed the quality control of the W-188/Re-188 generation system. Materials and Methods: Several quality control tests of the Re-188 eluate from generator were carried out of about 300 days. After elution of Re-188 with normal saline (20 ml), chromatogram and gamma-ray spectrum of Re-188 eluate were obtained. The presence of aluminum which was derived from the elumina bed of the generator was detected by using aluminum ion indicator kit. Re- 188 eluate was allowed to decay for several days, and then W-188 breakthrough in the Re-188 eluate was measured by detecting gamma-ray at 227 keV and 290 keV. The pH and the pyrogenicity of the eluate were checked. The Re-188 eluate from the generator was 67.4¡¾7.0% of W-188 during 270 days, and it was hightest at third day after previous elution. Radiochemical purity of Re- 188 eluate obtained from chromatogram was higher than 99%. Gamma-ray spectrum of Re-188 eluate showed a peak at 155 keV. Aluminum ion and W-188 contamination were not detected. The pH of Re-188 eluate was 3 and the concentration yield was 85%. Conclusion: Our experiments and results on quality control tests of Re- 188 eluate from W-188/Re-188 generator may be useful for setting W-188/Re-188 generator in hospitals.