Abstract: The Compressive creep behavior of as-cast Ag In Cd alloy with and without tin（Sn, 3wt%） was investigated by using the special modified apparatus on RDL50 creep tester at 300~400℃and compressive stress was in the range of 12~30 MPa.The relationship among temperature, stress and steady strain rate has been analyzed, the stress exponent n and apparent activation energy Q_a of the creep process have been calculated as well as the mechanism of compressive creep behavior have been discussed, based on the TEM images of microstructure. The results showed that, the steady strain rate of the alloy increased with the increasing of temperature and compressive stress.Compared with Ag In Cd, the stress sensitivity became more obvious and Q_a increased in each stress with the tin in it, indicating that the creep resistance of Ag In Cd Sn was better. The n of Ag In Cd were3.31, 4.09 and 5.77 under the 300℃,350℃,400℃ respectively, while of Ag In Cd Sn were 9.41,8.07 and 9.48. The Q_a of Ag In Cd were 68.1, 103.7, 131.6 k J/mol under 12, 18, 24 MPa, for Ag In Cd Sn, namely 147.9, 126.9, 149.9 k J/mol. There were lots of stacking faults in the TEM images under each creep condition, which played a critical role in the creep mechanism. Mechanical twinning was the main mechanism at 300 ℃ while dislocation climbing was the dominant mechanism at 400℃.