The N-substituted polyacrylamide containing aclicyclic amino rings，such as：poly-N-acryloyl-N’-methylpiperazine，poly-N-acryloyl-morpholine，poly-N-acryloyl-pyrrolidone，poly-N-acryloyl-piperidine，were examined as the protective polymers for the formation of the pre-cious metal colloids．It was found that in the presence of poly-N-acryloyl-morpholine stable metallic colloids with fine particle size and narrow dispersion of palladium，rhodium，plati-num，ruthenium and silver were formed by means of alcohol reduction in a methanol-water mixed solvent system．TEM measurements illustrated that in poly-N-acryloyl-N’-methylpipe-razine protective system，palladium colloid was mostly distributed in the range of 1.5—2.0 nm wkh an average diameter of 1.6 nm；in poly-N-acryloyl-morpholine protective system，palla-dium colloid was in the range of 2.0—3.0 nm with an average diameter of 2.5 nm，rhodium colloid was in the range of 1.6—2.5 nm with an average diameter of 2.3 am．Palladium，pla-tinum and rhodium colloids formed were also surveyed as catalysts for hydrogenation of cy-clooctadiene．