Several methods were given for metallographic preparation of iridium/rhenium composite obtained by chemical vapor deposition. Rhenium layer microstructure include column grain zone and fine grain zone near the iridium layer. Grain size was measured in both zones. Features of annealing twin crystal, V etch net and void of Kirkendall in grain boundary were studied. Grain image and growth features are studied through second electronic image of Iridium layer microstructure. Kinetic equation of Iridium grain growth is achieved.