A high-throughput combinatorial materials experimental apparatus for in-situ synthesis and real-time characterization includes a composition spread device to prepare continuous or discrete composition distribution as precursor of the high-throughput experimental samples library, a low temperature diffusion mixing device to thoroughly mix the composition spread in the thickness direction through diffusion at a relatively low temperature to form an amorphous precursor, and an integrated synthesis-characterization unit for heat treatment of the material library precursor in either a parallel or point-by-point scanning mode at different thermodynamic conditions for phase formation and to characterize features or properties of the materials of interest in an in-situ and real-time manner. The integrated synthesis-characterization unit includes a chamber maintained at desired vacuum and atmosphere, a micro-heating source, an excitation source, a signal collector, and a sample holder.