Heat transfer performance of minichannel was directly compared with impingement heat transfer by the impingement heat transfer system utilizing 1.27mm diameter and 6.35mm long 19 minichannels array. Two blocks with minichannel array were used to form an impingement cooling system. The heat transfer performance of the impingement jet was estimated in the form of dimensionless temperature from the result of three individual experiment for different thermal boundary conditions, which were utilizing combined blocks, upstream block and downstream block.