It is now well established that massive stars in star forming regions can trigger next generation of star formation. Theoretical simulations suggest two main processes for triggered star formation; the radiation driven implosion (RDI) process and collect & collapse (CC) process. In this talk I will discuss observational aspects of triggered star formation scenario. The young stellar objects (YSOs) in star forming regions have been identified using the near-infrared (NIR) and mid-infrared (MIR) observations. The age of the identified YSOs was estimated using the optical color-magnitude diagram. The age of YSOs, the morphology of the regions and the global distribution of YSOs indicate that the star formation can be triggered by either (RDI/ CC) of the processes.