In this study, a new method to increase the disperse dyeability of polypropylene fibers was investigated. For this purpose, dye bath having liquors to good ratio of 20:1 and dye concentration of 2% owf has been prepared and fabrics from polypropylene fibers were dyed by using ultrasonic energy. These experiments were done at different temperatures (200C, 400C, 600C and 80 0C) and different time intervals (1, 3, 5, 10, 15, 20, 25, 30 min). In order to evaluate the effect of carrier, dyeing experiments were repeated in the case of 1% carrier addition to the dye bath. Dyeing experiments were also repeated by conventional manner to compare the effect of ultrasonic power as well as the effect of carrier addition. The color strengths of dyed fabrics were examined by K/S values measured by a spectrophotometer. Therefore dyeability of polypropylene fibers was determined according to temperature, time and carrier. According to results, ultrasonic power improves the dyeability and addition of carrier gives better results.In this study, a new method to increase the disperse dyeability of polypropylene fibers was investigated. For this purpose, dye bath having liquors to good ratio of 20:1 and dye concentration of 2% owf has been prepared and fabrics from polypropylene fibers were dyed by using ultrasonic energy. These experiments were done at different temperatures (200C, 400C, 600C and 80 0C) and different time intervals (1, 3, 5, 10, 15, 20, 25, 30 min). In order to evaluate the effect of carrier, dyeing experiments were repeated in the case of 1% carrier addition to the dye bath. Dyeing experiments were also repeated by conventional manner to compare the effect of ultrasonic power as well as the effect of carrier addition. The color strengths of dyed fabrics were examined by K/S values measured by a spectrophotometer. Therefore dyeability of polypropylene fibers was determined according to temperature, time and carrier. According to results, ultrasonic power improves the dyeability and addition of carrier gives better results.