A method of forming a nano-particle array by convective assembly and a convective assembly apparatus for the same are provided. The method of forming nano-particle array comprises: coating a plurality of nano-particles by forming a coating layer; performing a first convective assembly by moving a first substrate facing, in parallel to and spaced apart from a second substrate at a desired distance such that a colloidal solution including the coated nano-particles is between the first and second substrate; and performing a second convective assembly for evaporating a solvent by locally heating a surface of the colloidal solution drawn when the first substrate is moved in parallel relative to the second substrate. The present invention provides the method of forming the nano-particle array where nano-particles having a particle size from a few to several tens of nanometers are uniformly arrayed on a large area substrate at a low cost, and the convective assembly apparatus for the same.