In this study, phase change material (PCM) microcapsules were prepared, andcopper nanoparticles were coated on the microcapsule surface through the sonochemicalcoating process for temperature regulation and antibacterial activities. n-octadecane andmelamine–formaldehyde resin were used as the PCM core and wall materials of microcapsules,respectively. It was observed that applying high-speed stirring above 7,000 rpm wascritical to form n-octadecane droplets in O/W emulsion with 3.5±0.5 μm in diameter usinga homogenizer. Spherical PCM microcapsules with 6.0±2 μm in diameter could beobtained at lower than pH 6. Copper nanoparticles could be successfully embedded onthe surface of PCM microcapsules through the sonochemical coating process. The PCMmicrocapsules coated with copper nanoparticles exhibited excellent antibacterial activitiesagainst S. aureus and K. pneumonia.