A process for making metal-matrix composites includes: purging a refining chamber filled with molten metal matrix in a furnace by an inert gas such as nitrogen gas; filling a reinforcing material, preferably with particulates, in a bucket suspended above the molten metal matrix filled in the furnace; applying a forced drafting on the reinforcing material in the bucket for subsequently upwardly drafting the reinforcing material from the bucket; and downwarddly forcing the uprising reinforcing material to be homogeneously distributed into the molten metal matrix under homogeneous agitation, for producing a metal-matrix composite reinforced with reinforcing material in a closed system wherein the nitrogen gas is served merely for Initially purging the air outwardly from the system, not being consumed continuously in order for greatly saving the nitrogen consumption and reducing the production cost thereof.