A macroscopic cell and three-dimensional fluid model have been used to investigate the discharge characteristics in ac plasma display panel cells of electrode-shaping configurations. Four kinds of non-standard geometries (i.e. D-, △-,W- and U-shape electrodes) have been considered. The characteristics of the discharge current, the operating voltage and the discharge efficiency of different configurations have been discussed. It is found that the discharge efficiency can be improved by about 10%-30% compared with the standard geometry, while the operating voltage increases slightly in the non-standard geometries. There is a trade-off between improving the discharge efficiency and lowering the sustaining voltage in design of plasma display cells by electrode shaping.