A heating system is disclosed, which includes a main body having a duct formed therein, an air flowing guiding member, and a heating unit. The duct has an air inlet and an air outlet. The air flowing guiding member is disposed in the duct. The heating unit includes a substrate and a plurality of electronic components disposed on the substrate in a matrix form and embossed from a surface of the substrate, wherein each of the electronic components is capable of individually producing heat to directly heat up the air flowing in the duct. Also a heating system using the heating unit is disclosed.