Abstract In this article, an attempt is made to measure the temperature at the interface between bit and rock samples were studies and the correlation of factors (bit diameter, spindle speed, rate of penetration, depth, thrust and torque) effects on interface temperature was investigated. The experiments were conducted on shale rock samples by using grounded thermocouples method. During rotary drilling operation effects of factors influence on temperature rise were determined. The most influencing factors are depth (0.718), thrust (0.744) and rate of penetration (0.553) have a strong and moderate positive correlation whereas, bit diameter and spindle speed has weak positive correlation of 0.267 and 0.108 respectively. This study shows that the quantitative degree of relationship between the operational parameters and interface temperature during rotary drilling.