Bio-based polycarbonates containing cyclic ketal moieties were designed, and the bio-based diol monomer was synthesized by CQ with glycerol to improve their thermal properties and replace BPA in polymer industry. The molecular structure of the novel bio-based diol monomer 2,2:3,3-bis(4′-hydroxymethylethylenedioxy)-1,7,7-trimethylbicyclo[2.2.1]heptane (abbreviated as CaG) was analyzed by 1 H, 13 C, and 2D-COSY NMR techniques. GPC results show that CaG was reacted successfully and led to the high molecular weights for homopolycarbonate (M w = 18 652) abbreviated as PCaGC and for copolycarbonate (M w = 78 482) as PCaG 20 BPA 80 C. The high thermal stability (T d value above 350°C) and glass transition temperature (T g value from 128 to 151°C) of PCaGCs and PCaG x BPA y Cs were studied by TGA and DSC, respectively. Given the sufficient reactivity and high thermal stability, CaG is a promising renewable building block for applicable polymers.