The effect of In incorporation is studied on the, micro-hardness compactness and elastic properties of glassy Se–Te–Cd alloys. The micro-hardness of glassy Se 75 Te 15 – x Cd 10 In x ( x = 0, 5, 10 and 15) alloys is calculated at room temperature. The compactness structure of Se 75 Te 15 – x Cd 10 In x alloys is also determined from the measured densities. The micro hardness is maximum for glassy Se 75 Te 5 Cd 10 In 10 alloy and compactness minimum for same concentration. The volume of the micro-voids, their formation energy and the module of elasticity are determined using the free-volume theory and are considered in terms of average coordination number ❬ Z ❭.The module of elasticity E is increases in starting with average coordination number reach maximum then decreases and the micro-void volume V h is minimum for glassy Se 75 Te 5 Cd 10 In 10 alloy.