Arylpiperazine derivatives referred in this article possessed antitumor activity, which were synthesized and crystallized through the gradual evaporation process. The molecular structures of 2-(4-(2-(4-phenylpiperazin-1-yl)ethyl)benzyl)isoindoline-1,3-dione (C27H27N3O2, 1), 2-(4-(2-(4-(4-bromophenyl)piperazin-1-yl)ethyl)benzyl)isoindoline-1,3-dione (C27H26BrN3O2, 2) and 2-(4-(2-(4-(4-chlorophenyl)piperazin-1-yl)ethyl)benzyl)isoindoline-1,3-dione (C27H26ClN3O2, 3) were determi-ned and described. - interactions were observed in the packing modes of three compounds, and compound 2 and 3 showed halogen interactions between molecules nearby, which were different from compound 1. The dihedral angle values, the bond lengths, bond angles and the parameters demonstrated that involvement of halogen atoms did affect the conformation, configuration and cell parameter of the compounds.