The thermodynamical and allied properties of (Pr1-ySmy)(0.7)Ca0 3CoO3 (0 <= y <= 1) were investigated in this paper by means of a modified rigid ion model (MRIM) with pair wise interatomic interaction potential. The calculated specific heat, bulk modulus, and other thermal properties reproduce well with the available experimental data, implying that MRIM represents properly the nature of the perovskite type cobaltates. The specific heats are found to increase with temperature and decrease with concentration (y) for the present cobaltates. The increase in Debye temperature (theta(D)) indicates an anomalous softening of the lattice specific heat due to increase in T-3-term in the specific heat occurs with the decrease of y. (C) 2013 Elsevier Ltd. All rights reserved.