A two-dimensional simulation of reactive ion etching (RTE) of InP trench profiles is developed. The local equation of etching rate on each string is established considering the Langmuir adsorption concept. The etching rate takes into account the chemical etching on both the covered and uncovered surface fractions by the neutrals and the ion sputtering on both the covered and uncovered fraction of surface elements. Surface kinetic parameters of InP RIE process are estimated by using a minimization method to fit the experimental data of etching rate as a function of percent CH4 in the CH4-H-2 plasma mixture. Such parameters are then used to simulate the etch surface profile evolution in time under the RIE process. The effect of ratio of the ion flux to the neutral flux on the anisotropy of the profiles is shown as well as the aspect ratio on the etching rate evolution in time.