Metamorphic III-V epitaxial solar cells for high-efficiency multi-junction solar cells have a problem with the nonuniform property in the wafer. In the low open circuit voltage (V_oc) cell, the cell layer was divided into several areas in the in-plane as grains with dislocation glide planes dominated by surface steps and InGaP superlattice. In this study, the in-plane distribution of dislocation glide planes in five 1x1 cm²solar cells was evaluated by the reciprocal space mapping and compared with the solar cell characteristics. V_oc tended to decrease as the InGaP SL dominating area increased.