The objectives of this study were to find out the effects of Biot number (Bi) on the distribution of temperature in a cubic-shape solid object during the unsteady state and to determine the value of Biot number that generated homogenous distribution of temperature from time at all positions.This study was carried out by solving a mathematical model which was suitable to the problem, namely the fourier equation for heat conduction. It utilized a numerical computation approach using explicit technique of finite difference menthod. The temperature of the object at initial condition washomogenous. Meanwhile, all boundary conditions were in contact with the fluid whose temperature (T) and coefficient of convection (h) were kept constant and homogenous from time to time. The specific gravity (p), specific heat (c), and coefficient of heat conduction (k) of the object were assumed fixed or unchanged against the temperature changes and were homogenous at all positions or not the function of position. During the process of unsteady state, the object did not experience any change in both form and volume. from the results of this study, we concluded that (1) the higher the value of Bi, the less homogenous was the distribution of temperature from time to time; (2) for Bi = 0.01, the distribution of temperature generated from time to time could be considered as homogenous with the value of 0max=4,23%.