This paper introduces the monolithic cast modular box system, which is developed by Beijing Building Research Institute of CSCEC and produced by New Star Boxed Construction Unit Factory, and the new type modular box assempled with precast flat mould concrete, which is developed by Beijing Dongsheng Boxed Construction Unit Factory, and compares their advantages and disadvantages on the form, construction, production technique, connection and behavior, which may provide a reference for the progress and development of the modular box system.