The dependence of the rate constant of electron-ion recombination on the external electric field in systems characterized by high electron mobility is calculated by means of computer simulation. Two simulation methods are proposed, applicable for high and low electric fields, respectively. The rate constant is found to decrease with increasing electric field, the effect becomes stronger as the electron mean free time increases. Results obtained with the energy and the space criterion of recombination are discussed and a comparison of the simulation results with experimental data is included.