RS-232 serial communication has to be adopted in the communication between computers and some equipments without TCP/IP enclosed. First, the main properties and events of MSCOMM32.ocx component are discussed in this paper. And then we expatiate on the method of using the MSCOMM32.ocx component to obtain serial communication under Delphi environment via a real application example of Telecommunication industry. In the mean time the designing framework implementing the serial communication is presented. At last we discuss the problems that should be considered in the communication control program.