According to laboratory accelerated test data, stress corrosion cracking (SCC) in structural metal materials occurs by initiation and coalescence of micro cracks, subcritical crack growth, multiple large crack formation and final failure under the combination of materials, stress and corrosive environment. In this paper, a computer simulation model for the process of SCC has been proposed. The procedure is as follows: The possible number of crack initiations is set for a given space and the initiation times for all cracks are assigned by random numbers based on exponential distribution. The sites and length of the cracks are assigned by uniform random numbers and normal random numbers, respectively. The coalescence of cracks and the subcritical crack growth are determined based on the fracture mechanics. The simulation is terminated when the maximum crack length reaches a critical value or all of the possible number of cracks is initiated. The results obtained in this paper indicate the applicability of the present model to predict the SCC behavior in real structures based on the laboratory accelerated test data.