Single crystals of RAlO3 (R : Dy, Ho and Er) were grown using the Czochralski technique. The magnetization of the single crystals along the a-, b- and c-axes was measured in the paramagnetic region using a superconducting quantum interference device (SQUID) magnetometer. Using these values of the magnetization, the magnetic entropy change, which depends on the crystal axis direction, was calculated. Single crystals of DyAlO3 oriented along the b-axis and c-axis oriented ErAlO3 single crystals are promising materials for use in magnetic refrigeration systems using the Carnot cycle in the temperature range between 4.2 and 20 K.