We derive the one-variable polynomial fusion rings of the A and D seri
es of the SU(2) conformal models and of the minimal models of the Vira
soro discrete series from the quantization of the SL(2, R) Chem-Simons
theory with fractional charge. Moreover, we associate a fusion ring w
ith positive integer structure constants to the Kac-Wakimoto set of ir
reducible representations of the SL(2, R) current algebra.