In order to evaluate power quality more accurately and synthesize the characteristics of the distribution, which has nodes in large quantity and area, an online power quality monitoring system (PQMS) is developed by using the digital signal processor (DSP) and the general packet radio service (GPRS). This PQMS consists of two parts: the power quality monitor (PQM) which is designed on the structure of DSP and the monitoring software (MS) in upper computer which is designed on the platform of LabVIEW. GPRS network provides the communication channel for these two parts. Therefore, supervisors can monitor and analyze the power quality from a long distance. In this paper, the design and realization of each part are described in detail. Experimental results show that the proposed system is fast in response with high accuracy and has the ability of real-time processing.