Abstract: Investigation were made using mathematics on the thermal parameters of end chills in sand mold, Those parameters include transient temperature, thermal absorption and their derivatives, This paper offers a group of mathematical formulas for calclation of those parameters, By means of practical measuring, the fair coherence between the results calculated from corresponding forulas and the data got from experimental tests shows that those formulas are applicable in case of the value<0.4, Furthermore, based on the offered formulas a discussion is presented conerning the main factors that affecting those parameters, A nearly linear relationship hetween the thermal absorption Q and temperature gradient of castings is deduced.