Abstract: The present inventions provide a novel polycarbonate copolymer having high fluidity and high molecular weight which is formed of a structural unit derived from an aliphatic diol compound and a structural unit derived from an aromatic dihydroxy compound, having a structure represented by the formula (III): having the content of the structural unit derived from the aliphatic diol compound of 1-30 mol %, having the Q-value (280° C., 160 kg load) in the range from 0.02 to 1.

Abstract: [Problem] To provide a process for manufacturing, easily and using a conventional branching agent, a branched aromatic polycarbonate resin which has both a sufficiently high molecular weight and a desired degree of branching. [Solution] A branched aromatic polycarbonate resin having a degree of branching (N value) controlled within a specific range is manufactured by subjecting an aromatic polycarbonate prepolymer that has a branched structure introduced using a specific amount of a branching agent to molecular-weight-increasing linking reaction with an aliphatic diol compound in the presence of a transesterification catalyst under the condition of a reduced pressure. The amount (A) of the branching agent used in adjusted on the basis of the correlation between the amount (A) of the branching agent used and the N value of the branched aromatic polycarbonate resin.