Abstract: The SCADA system in the Looped Dong-Huang Pipeline is the industrial control system imported for realizing automatic tight - line transportation, and it has been in operation since its commissionning in 19.91. For the purpose of evaluating its availability, the SCADA system is discussed and analized in relation with its functions and reliability based on a series of conparison, statistics and calculations. As one of the technical indexes for eveluating computer based control system, functions reflect the controllability over production process, while reliability shows the execution of its funtions. It is confirmed by analysis that the said SCADA system has realized centrol supervisory control and data acquisition, and it is feasible in design, and has a high reliability, and can be regarded as an exemple for other applications.