Pineal bodies usually contain a concretion called brain sand. Concretion is mostly composed of phosphate and calcium carbonate. The concretion increases with age, however the origin and mechanism of formation of these materials are not clearly understood. Calcified bodies are usually used as a guide in radiographic studies. Due to the importance of these materials, this research was done on brain sands in sheep brains. In this research, 24 specimens of pineal glands were collected from sheep at the ages of 3, 4, 6 and 7 years. They were then fixed in boin's Fluid for 8 hours and then put in 70% ethanol. After 72 hours, the specimens were stained by Von Kossa and studied with light microscope. For studying pineal body, 6 whole brains were put in10% formaldehyde for 2 months. Results showed that brain sands were only seen in 7 years old sheep in the central part of pineal glands.