A process for preparing m - dichlorobenzene by atmospheric selective transfer reaction of p - dichlorobenzene in the presence of alcl3 and h2o is described . effect of selectivity of the reaction is discussed . the best technological conditions are determined 阐述了常压下对二氯苯在催化剂无水三氯化铝及助催化剂水的存在下发生转位反应,高选择地制取间二氯苯的工艺过程;讨论了影响产物选择性的有关因素,确定出适宜的工艺条件。