In recent years, in order to cut down the production cost, substrates with large area are used in semiconductor industry, especially in the field of thin film transistor display. Obviously, the key point for the substrate fabrication needs a uniform plasma sources with large area. Among them, inductively couple plasma is one of the good candidates. In our experiments, based on a small chamber of inductively coupled plasma with a single multi-turn coil, we investigated the relationship between coil configuration and power coupling efficiency, and applied these experimental results to the generation of large-area inductively coupled plasma with parallel-connected multi-sources. By using Langmuir probe measurement, plasma parameters of this kind of large area ICP were characterized. It was shown that the large-area ICP source with parallel-connected multi-sources can produce a plasma density lager than 1010cm-3 under a rather low pressure (<10Pa). The uniformity of plasma density and the photoresist etching can be controlled to a level better than 80% by adjusting the process parameters.