The Development of a microcomputer-based SCADA system composed of amicrocomputer as a master station and many microcontroller based remote stations. TheSCADA system use an IEEE std 999-1992 protocol to implement the data communicationbetween a master station and many remote stations. The Intel 80C32 microcontrollerwas applied for a remote station, encoder and decoder circuits. The SCADA softwarewas developed on the master station by using Visual BASIC to acquitted the data anddisplay on the CRT monitor of the microcomputer. The experiment on IEEE std 999-1992protocol found that the data communication work very well. The encoder and decodercircuits can detect error and correct the data, these increase efficiency of datatransmission. The SCADA system by using IEEE 999-1992 protocol is easy todevelop, low cost systern and easy to interface to other equipment's.