This study was conducted to compare biological treatment processes for uneasily biodegradable dyeing wastes with trickling filter(TF), activated sludge(AS) and their combination processes; TF/AS, AS/TF, TF/SC(solid contact) and RF(roughing filter)/AS. In addition, the effects of developed and specific bacterial strains applied to activated sludge were also compared. The COD removal efficiency of trickling filter was better than that of activated sludge. It appeared that total COD applied to trickling filter was removed about 35% by biooxidation, 10% by air stripping and chemical oxidation, and 20% by adsorption and settling. In comparison to individual process, the COD removal efficiencies of combination processes were not greatly increased. While the constructed Pseudomonas putida was failed to acclimate to dyeing wastes, mixed strains with specific strains slightly enhanced the treatment capability. The treatment capability of A stage in A/B process showed little improvement but the improvement seemed to be greatly affected by DO and temperature of A stage.