A novel Polycarbonate melt-process was developed instead of interfacial-process,in which a direct synthesis of diphenyl carbonate from phosgene and phenol was employed. Lower environmental load and energy saving were achieved andpolycarbonate with excellent quality was also obtained by the Mitsubishi Melt-Process. The process was assessed from the view point of green sustainable chemistry by means of i-Messe proposed by Japan Chemical Innovation Institute, and proved to be superior to the interfacial one.