Abstract: Temperature and pH could have an effect on the solubility of borate in solution.When the borate solution was under the condition of 8≤pH≤11，the saturation concentration of boron increased with the rise of temperature，but when pH was 12，the saturation concentration of boron increased first and then decreased.When the temperature was at 30~60 ℃，the saturation concentration of boron decreased first and then increased with the rise of pH，but when temperature was 70 ℃，the trend of saturation concentration decreased first and then increased and decreased in the end.The experiments analyzed the liquid phase and solid phase of saturated borate solution based on Raman spectra and X-Ray Diffraction.The existing forms and interaction of polyborate anions were further discussed.The experiments proved that when pH was higher，there were more low-polymerized borate anions. The existing forms mainly were B（OH）4- and B2O（OH）62-。

Key words: saturated borate solution, temperature, pH, polyborate anions