Abstract: In 10 MW High Temperature Gas-cooled Reactor (HTR-10), it is inevitable to cause the wear of graphite components and generate the graphite dust, which can adsorb solid fission nuclides and probably affect the normal operation of the reactor. In order to analyze the dust size distribution, the microstructure and the adsorption characteristics of the dust surface, a radioactive graphite dust sampling loop with high-performance sintered metal powder filter elements was built at the entrance of the helium purification system of HTR-10. The filtration mechanism, the pressure drop characteristics and the filtration efficiency of the filter elements were analyzed so as to investigate the filtration results from the radioactive graphite dust sampling loop. An experimental setup was designed and built to measure the filtration efficiency of the sintered metal powder filter elements. The experimental results indicate this kind of filter can remove most of the dust particles in the test air flow, and thus it can accomplish the high performance filtration sampling of the dust including the radioactive graphite particles suspended in the primary coolant of HTR-10.