Abstract: Muscle soreness and damage often occur after selective exercise routines, the severity of damage and soreness vary as a function exercise protocol. Purpose: This study was designed to examine the effect of single-leg squat and agility tests on Delayed Onset Muscle Soreness (DOMS). Sixteen male subject group from different sports participated in this study, with the mean (age 18.06+ 1.53 years, body mass 68.69 + 8.63 kg, body height 172.69 + 7.03 cm and training age was 6.38 + 3.03 years). Resting blood samples were drawn from the heated hand vein catheter immediately before using exercise protocol test and after recovery periods of 24 and 48 h for the measurement of Creatine kinase (CK) activity in serum .The participants in this study began the experimental protocol test by using single-leg squat. 30 minutes later the same subjects were exposed to agility test in the same training unit until each one of them reached voluntary exhaustion. The results showed that significant CK elevation 24 h after Appling the exercise protocol test compared to CK level before it was conducted, However the results also revealed that the change percentage between (Pre &post 24h was 81.4%) for measurement after 24 h recovery, and Significant decrease of CK after a period of 48 h recovery as compared to the level of CK 24 hours after it was conducted. Furthermore, the change percentage between (Post24&post 48 h was 47.79%) It was concluded that a significantly faster recovery of CK during 48 h recovery may depend on two factors: (1) training state of study subjects (2) Reduced muscle soreness after 48 h of recovery period as a result of the decreased damage response to such particular exercise protocol tests.