Pointer alias analysis plays an important role in the parallelizing optimization of C program, however, all the previous analyzing algorithm can only be used to analyze the pointer scalars. In this paper, an extended representation for point-to information is presented, which can represent not only the point-to information of pointer scalars, but also the point-to information of pointer arrays. Furthermore, an algorithm of intraprocedural alias analysis for pointer array is presented. This algorithm comprises both the pointer scalar analysis and pointer array analysis. It can be used to efficiently solve some problems which couldn't be solved by the previous algorithm.