Abstract: The values of specific contact resistance (p₀) for both Au/n-InP and Au/p-InP have been calculated theoretically based on the carrier transport study of metal-semiconductor systems. The results, which are presented graphically, show the dependence of p₀ on impurity concentration from 10¹⁸ to 10²¹cm^-3, and the barrier height from 0.3~1.0 eV. It is found that the Schottky barrier height (φ_B) would not be changed with annealing temperature below 350℃ in 3 min. When the annealing temperature is higher than 350℃, a poor ohmic contact will be formed in the case of Au/n-InP system, but for Au/n-InP system, only a reduction of φ_B will be observed. It is determined that an obvious alloying takes place at about 350℃. The computed theoretical results are used to interpret the experimental data of Au Zn/p-InP ohmic contact published in the literatures and the problems exist in our p-type ohmio contact technology are discussed.