In the past years, due to the rapid growth of high-tech industries, the power supply requirements are becoming much stricter. Many of sensitive equipments are often affected by various power quality (PQ) problems to malfunction, as a result, the customer complaints. Before the mitigations of PQ are decided, the PQ monitoring system should be setup to find out the causes of PQ problems. The aim of this thesis is to establish a PQ monitoring system to investigate the quality of power in Kaohsiung Area for different types of customers. The recorded data not only are used to calculate different PQ of various parameters indices such as harmonics, voltage unbalance, voltage flicker, and voltage events, but also to confer the levels of typical devices affected by voltage sag events. The related measuring techniques include selection of monitoring sites, threshold settings of recorder, the ability to capture events, and the data collection and analysis are included in this thesis. Analysis results are compared to PQ standards to understand the actual quality of power delivery in the Kaohsiung Area.