This paper investigates the physical dependence of the Early voltages VA（I）and VA（V） of a bipolar junction transistor having an arbitrary base doping distribution. A simple expression for the relationship between VA（I） and VA（V） is obtained. The current dependency of VA（V） is also given which shows that VA（V） will begin to decrease at a little high injection and can be less than VA（t） due to the bass correction factor. It is pointed out that it seems doubtful to determine the dominant mechnaism limiting the current amplification factor from the measured output conductances

owing to not only the variation of VA（V） but also the existence of the doping-profile-dependent correction factor.