Calcium absorption of standard milk is influenced by types of fat, other than types of calcium salts, vitamin D, PTH hormone, etc. However, calcium absorption on different fat content, particularly on milk, has not been reported. The purpose of this study was to determine the effect of the fat content of milk on the absorption of calcium carbonate and calcium phosphate mixture in rats. Experiments were conducted using 24 male Sprague Dawley rats fed with low-fat milk (0.5% fat), high-fat milk (26% fat), standard milk (8% fat) and without milk for three weeks. Amount of feed consumed, feces and urine samples were collected to determine the amount of absorbed calcium for five days in the third week. Calcium content in the samples was analyzed using AAS (Atomic Absorption Spectrophotometry). The results showed that there were no difference in calcium carbonate and calcium phosphate absorption among rats fed with low-fat milk, high-fat milk and standard milk. The calcium absorption level from milk reached an average of around 98.67±0.22%. The absorption level of calcium carbonate and calcium phosphate mixture from milk was higher than control rats that were not fed with any milk. Fat content in milk did not affect the absorption of calcium carbonate and calcium phosphate mixture, but the milk consumption could increase the calcium absorption, compared to control.