Abstract: The model of integrated bipolar transistors advanced in this paper has made many improvements on 1-D(one-dimensional) modular model, and has spread the latter into high bias and high-level injection ranges. It can deal with the widely representative graphs of four basic transistors and other graphs.Using this model program, the EM₂ or GP model parame- ters of bipolar transistors can be obtained from their process and geometric parameters, An overall model of multiple-emitter transistors is also presented in this paper which is relatively accurate but simple. The results computed by means of this model for individual transistors and IC's (integrated circuits) accord relatively well with those measured.