The forward bias current-voltage (I-V) characteristics of Sn/p-InP (MS) contacts are studied over a wide temperature range of 80-400 K. The effects of series resistance (R(s)) and hole-tunneling factor on I-V characteristics are investigated. The R(s) is significant in the downward curvature at high forward bias region. The values of ideality factor (n) and zero-bias barrier height (Phi(Bo)) obtained from I-V-T measurements were strongly temperature dependent. While the value of n decreases with increasing temperature, Phi(Bo) increases with increasing temperature. Also, the value of R(s) gives a peak about room temperature. Such behaviors of n and Phi(Bo) have been attributed to distribution of interface states (N(ss)), inhomogeneity a native interfacial insulator layer and barrier height (BH). However, the effective BH (Phi(Beff)) calculated from modified saturation current is decreased with increasing temperature according to literature.