Abstract: Helium desorption rule from aged uranium tritide was investigated through the pressure measurement and the composition of helium released from uranium tritide stored at room temperature was analysed. After 6 to 7 years aging of uranium tritide, about 38.1%-45.3% He prodeced by disintegration of ³He from uranium tritide was released in the cavum of the uraniumbed with the gas pressure of 1.11-1.36 MPa and the purity of 99.9% above, the rest of helium is kept in the solid of uranium tritide with the He/U ratio of 0.177-0.201.