Temperature is one of the most important design challenges. So thermal awareness is mandatory in chip design. We propose early level thermal analysis and thermal aware design flow and show early level thermal aware floorplan optimization of CMOS image sensor. We developed the analysis flow that automatically extracts design information from the tools used at very early design stage for floorplanning and power budgeting such as spreadsheet and drawing tools. These information are fed directly into thermal analysis tool. It eables analysis of thermal impact on design at early stage and helps to make right design decision.