Abstract: The carbon films coated on the inner surface of quartz ampoules in different technological conditions were tested and analyzed by microscope and thrust analytic instrument.The morphology and etching pits of crystals,which grew in these ampoules,were also observed.The effect of the technology parameters on the surface topography of carbon films and the binding force between carbon films and the inner surface of quartz ampoules were studied.And the preferable technical parameters of carbon coating are obtained,i.e.the gas-flow rate of 600 ml/min,carbon coating temperature of 1060℃～1100℃,the carbon coating time of 30 minutes and the cooling time of 11h.Under the condition,the thickness of carbon films is more uniform and its binding with quartz ampoule is much stronger.Moreover the as-grown AgGaS₂ crystal is transparency,it has smoother surface and lower dislocation density.