The InGaN/GaN multiple quantum wells (MQWs) were grown by using a novel six-wafer reactor designed for the GaN based metal organic chemical vapor deposition system. It was found that the composition of the well layer of MQWs was significantly influenced by the rotation speed of the substrate during growth at atmospheric pressure. The structure of the MQWs has been studied using the transmission electron microscope (TEM) and X-ray diffraction (XRD) measurement. The MQWs grown at a rotation speed of 5 rpm shows several small wells within one well layer. But MQWs grown at a rotation speed of 20 rpm shows that the well layer is uniform and no any small well appears. Compared with that of the MQWs grown at a rotation speed of 5 rpm, the XRD spectrum of the MWQs grown at a rotation speed of 20 rpm shows a higher intensity and more satellite peaks. Additionally, it is deduced that the residence lifetime of Indium atoms on a nitride surface is about 1.5s. (C) 2002 Elsevier Science B.V. All rights reserved.