A microindentation test of CdS single crystals is performed on the {001}, {101¯0}, and {12¯10} surfaces using the sublimation method. The plastically deformed region around the indentation mark is measured by using the chemical etching technique and the optical microscope. The typical dimension of etch‐pit arrayr&mgr;m caused by indentation is assumed as a radius of the plastically deformed region. The main results obtained are as follows: (1) The swellhfrom the crystal surface is 2–3 &mgr;m on the {101¯0} surfaces when the load of identerWis 2.94 N. (2) The microhardnessHvon the (0001) surfaces revealed the asteroid pattern and the rosette pattern are distributed 100 to 140 and 95 to 130, respectively. (3) The functional relation between the load of indenterWN and ther&mgr;m isr=53.3 (W−0.127)1/2for the asteroid pattern andr=99.9 (W−0.145)1/2for the rosette pattern of the etch pits on the (0001) surfaces.