Unexpected fluorescence of POIY(alpha,beta-L-malic acid) (alpha,beta-PMA) without traditional fluorophore was observed firstly. This fluorescent polymer was synthesized via melt polyconclensation Of L-malic acid. The polymer was characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermogravirnetry (TG), Fourier transform infrared spectroscopy (IR), Fourier transform Raman spectroscopy (Raman), and X-ray powder diffractometry (XRD). The high molecular weight alpha,beta-PMA was synthesized by the optimum polycondensation at 130 degrees C for 15 h, followed by fractional precipitation with diethyl ether and petroleum ether. The degree of branching of a,alpha,beta-PMA was from 10% to 20% according to the reaction condition. Terminal group of alpha,beta-PMA was