purpose: The purpose of this study was to investigate the effect of four weeks interval training with creatine supplementation on body composition and sprint performance in amatory female swimmers. Methods: Subjects consist of 30 female from Ahvaz City (average age: 22٫10 ± 1٫41, mean weight: 57 ± 6٫31 kg) were selected and randomly divided in three equal groups of supplement, placebo and control. The subjects in supplement group ingested 20gr (2x10gr per day) creatine supplement per day for five days (loading phase) and then ingested 2gr per day for 25 day (maintenance phase). In placebo group, the subjects ingested the same dose of placebo at the same time. The supplement and placebo groups participated in swimming interval training by 85 90% of maximum heart rate for four weeks. The control group didn't ingested supplement and didn't participate in training. body compositions factors of subjects were evaluated by performed body composition test and for evaluation the sprint performance, subjects performed the 25m swimming test. All of the subjects performed these tests before and after 4 weaks training. Results: The results suggested that four weeks interval training with creatine supplementation lead to no significant changes in body compositions factors in supplement and placebo groups. But four weeks interval training with creatine supplementation lead to significant changes in sprint performance in supplement and placebo groups. Conclusion: Therefore these results suggest that creatine supplementation lead to increase in muscle creatine reserve, improvement in ATP-Pe system and then lead to improvement in intensive short distance performance. In the other hand, the subjects were amatory and one of the factors that improved the records of sprint performance (in tow groups) may be learning and effects of training.