In this paper, the function and usage of the application program interface of the KIT plant data acquisition system used in Unit 1 & 2 of LingAo Nuclear Power Station is analyzed and studied. A Web-based on-line process data display and monitor system has been developed by our own methods. Functions of collecting and publishing process data on a real-time basis, remote monitoring of production process, and fault diagnosing of instruments and sensors are implemented. In addition, application of a neural network based intelligent data processing system in predicating generated electrical power in nuclear power station is discussed.