3-pyridylboronic acid is prepared by reactants of 3-bromopyridine C₅H₄NBr as a starting material, n-butyllithium(n-Buli) and tributylborate(B(OC₄H₉)₃). Effects of the mole ratio of reactants, reaction temperature, reaction time and pH on the yield were investigated. Purity and structure of the product were characterized by HPLC, FTIR and ¹H NMR. The optimal reaction conditions for the synthesis of 3-pyridylboronic acid are obtained as follows: -65 ℃, 60 min, the molar ratio of 1.00∶1.20∶1.20 (n(C₅H₄NBr)∶n(n-BuLi)∶n(B(OC₄H₉)₃) and pH 5.0. Under the optimal conditions, the product yield and its purity can reach 82.20% and 99.50%, resgectively.