Abstract A practical method to determine glass transition temperature T g in molecular dynamics (MD) simulation is proposed. The method is applied for a fluorozirconate glass under various pressures. The values of T g are `kinetically' determined as the temperature at which the arrested time of constituting ions reaches to a predefined value. The arrested time is estimated as the time at which the mean-square displacement (MSD) exceeds a predefined value. The scatter of `kinetic' T g is obviously smaller than that of `thermodynamic' T g. The present method is practically useful in order to determine T g in the MD simulations of multi-component ionic glasses.