Electrical properties and the acceptor energy level in Zn‐dopedp‐Ga1−xAlxAs (0<x<0.85) prepared by liquid‐phase epitaxy have been investigated. During the LPE growth of Zn‐dopedp‐Ga1−xAlxAs layer, Zn diffuses from Zn‐doped Ga‐Al‐As melt into the undopedn‐GaAs substrate to form thep‐GaAs region. The modified van der Pauw method proposed by Petritz was used to measure the electrical properties ofp‐ (GaAl)As andp‐GaAs. The resistivity and the hole concentration of Zn‐dopedp‐Ga1−xAlxAs were found to be strongly affected by the acceptor energy level for Zn. The acceptor energy level in Zn‐dopedp‐Ga1−xAlxAs was found to increase from 15 meV forx=0 to 90 meV forx=0.85. The increase of the acceptor energy level with increasingxhas been theoretically explained by the modified hydrogenic model proposed by Baldereschi and Lipari.