The aim of this study was to investigate the effect of various Ca:tP ratios due to addition of microbial phytase and vitamin D3 on the performance of broilers. Throughout the study, rations that contained 2 different (1:1 and 2:1) Ca levels were prepared such that 1st group (Ca:tP ratio is 1:1), 2nd group (Ca:tP is 1:1+D3) 3rd group (Ca:tP ratio is 1:1+D3+Phytase) where Ca:tP ratio is mainly 1:1 and furthermore 4th group (Ca:tP ratio is 2:1), 5th group (Ca:tP ratio is 2:1+D3) and 6th group (Ca:tP ratio is 2:1+D3+Phytase) where Ca:tP ratio is 2:1 In these rations, vitamin D3 and Phytase levels are 5 μg/kg and 600 U/kg respectively. During the study, it was observed that the live weight gain of the groups that have Ca:tP ratio as 1:1 was better than the groups that have Ca:tP ratio as 2:1 Addition of phytase enzyme made this better (p<0.05). In the same way, the addition of phytase enzyme to the ration has increased the feed consumption and the feed conversion. According to the results of this study, it was observed that Ca:tP ratios used in broiler ration affect the weight gain and phytase enzyme increases the performance of broilers.