Bacteria exopolysaccharide （EPS） are high molecular weight biopolymers secreted into the surrounding environment during growth and metabolism. EPSs can enhance the resistance to oxidative stress， dryness and host defense factors， rendering the bacteria additional survival advantages. Bacteria EPSs are widely applied in food， chemical， pharmaceutical， cosmetics and petroleum industries in the form of emulsifiers， gelling agents， thickeners， water-retaining agents， preservatives， stabilizers， etc. Bis-（3'-5'） cyclic di-guanylate acid （c-di-GMP） and cyclic dimeric adenosine 3'-5'-monophosphote， c-di-AMP） are two novel emerging second messengers and can be found in a great many bacteria. Numerous researches show that c-di-GMP and c-di-AMP mediate the signal transduction of various physiological functions， including fatty acid metabolism， potassium ion homeostasis， biofilm and EPSs biosynthesis. This article summarizes and analyzes the metabolism of c-di-GMP and c-di-AMP and the molecular mechanism of EPS biosynthesis mediated by these two message molecules to provide the molecule basis and research directions for signaling network of c-di-GMP and c-di-AMP.