The sealing and tribological properties of combined packing of flexible graphite ring and braided packing ring were investigated through reciprocating motion tests on a new testing rig.The effects of axial stress, cross-section shape and density of flexible graphite ring on sealing and tribological properties were analyzed.The results show that the leakage ratio of combined packing is decreased significantly with the increase of axial stress, but the friction force is increased markedly and results in accelerated wear process, thus the service life of the packing is greatly shortened.The comprehensive performances of combined packing can be improved by optimizing the cross section shape, and V-shape graphite packing has better sealing and tribological properties than flat shape graphite packing.The combined packing with a graded density has better sealing and tribological properties than the combined packing with the same density.For the combined packing with the same density, the recommended density value of graphite ring is 1.5 g/cm3.