A polyester/polycarbonate blend having superior transparency and heat resistance which is useful for producing transparent polyester articles is disclosed. The blend of polyester and polycarbonate includes (a) polyethyleneterephthalate (PET) prepared with terephthalic acid component and ethylene glycol component, or copolymerized polyethyleneterephthalate prepared with terephthalic acid component and ethylene glycol component, and further copolymerized with 1 to 10 mol % of isophthalic acid, cyclohexane dimethanol (CHDM), di-ethylene glycol and/or alkylene glycol of 3 to 6 carbon atoms component with respect to acid or diol components; (b) polycarbonate (PC); and (c) CHDM modified PET prepared with 20 to 80 mol % CHDM with respect to diol components, wherein the amount of the PC is 10 to 60 wt % with respect to the mixture of (a) PET and (b) PC, and the amount of the (c) CHDM modified PET is 0.2 to 2.5 times by weight with respect to the amount of (b) PC.