UKIRT/WFCAM observed regions (square) overlayed on the Herschel three-color composite image (blue: 150, green: 250 and red: 500 μm). The regions are referred to as Region-1 to Region-4 starting from the southwest in a clockwise way, and the field of view is 13.75^′ × 13.75^′ for each region. In this paper, we focus on objects in Region-2, the most active star forming region. The northern half of Region-4 was regarded as an off-cloud reference field.