Abstract: This paper discusses how to develop the method of the OOP serial communication component under windows95 and NT by delphi3.0.It supplies original program and makes it quite convenient to program the software of serial communication of control in delphi.We can educe the method enhancing the ability of developing the program by expanding component of delphi.It is easily realized that the information exchanges between the microcomputer and the intelligentized instrument under windows95 and NT by the component.This exchange technology was successfully used in the ultrasonic liquid member analyse instrument and the microcomputer artificial fur weave flower system.It has some practical significance to intelligence instrument、CAD、CAM and the computer controlled systems.