Sodium metaborate tetrahydrate (NaB(OH)4·2H2O) was synthesized by reaction of anhydrous borax (Na2O·2B2O3) with sodium hydroxide (NaOH) under conditions at 90 ℃ for 150 min. The structure was characterized by Xray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and Thermogravimetric (TG) analyses. Moreover, dehydration kinetics of NaB(OH)4·2H2O was carried out under non-isothermal conditions and the Coats-Redfern method was applied to analyze the TG data for calculation of activation energies (Ea) and pre-exponential factors (ko) for different heating rates. It was determined that dehydration of sodium metaborate tetrahydrate occurred in five steps. According to the Coats-Redfern non-isothermal model, Ea and ko were calculated as 50.89 kJ/mol and 26×10^(4) min^(-1) for region I, 18.51 kJ/mol and 0.87×10^(3) min^(-1) for region II, 15.72 kJ/mol and 0.52×10^(3) min^(-1) for region III, 4.37 kJ/mol and 0.04×10^(3) min^(-1) for region IV and 37.42 kJ/mol and 8.56×10^(3) min^(-1) for region V, respectively.