Selection of appropriate types of collectors as the main basis of flotation can have a significant impact on the process efficiency. In this regard, 2, 5-Dimercapto-1, 3, 4-thiadiazole (DMDT) was introduced as a new collector. And, its performance was compared with the prevalent collector C7240 (a mixture of 10–20 wt% sodium alkyl dithiophosphate and 20–30 wt% sodium mercaptobenzothiozole) and Sodium Isobutyl Xanthate (SIBX) on the flotation of copper sulfide ores. The effect of the reagent dosage (collector and frother) and pH level were studied using a design of experiment (DOE). Results showed effect of factors was significant in the case of copper recovery and grade of product. Consequently, the optimum range of the DMDT was 8 g/t at pH=11.8 in which the maximum grade and recovery were obtained. Also, the application of chemical agents also had a significant effect on flotation performance, so that the result of sequential addition of the collector indicated significantly improved recovery and grade. The use of a combination of collectors resulting in both physisorbed and chemisorbed surface products can also affect the froth structure and influence the final grade achieved. Accordingly, the best route of collector addition was DMDT at first, then C7240, and finally SIBX. Through this offer, the maximum recovery and grade of product were achieved 86.2% and 14.1% respectively. So, DMDT as a mixture of two others has a positive effect on the copper flotation efficiency.