Basingthe titration to analyze the total boron, total alkalinityand made references to the determination of serum bicarbonate, we have developed a new method by combining UV spectrophotometry and titration to determine CO2-3 and HCO-3 values accurately in boron-containing brine. The effects of spectrophotometric reaction were studied by analyzing the wavelength, the dosage of chromogenic reagent, temperature and pH, choosing phonel red as chromogenic reagent. The further research was studied by analyzing the linearity between the absorbance and the concentration, the detection limitation, the recovery rate and so on. The results showed that the maximum absorbance peak is at 558 nm. There was a good linear relationship in the ranges of 0～10.0 mmol·L-1, correlation coefficient R2=0.999 8. The detection limitation is 2.53×10-3 mmol·L-1. The recoveries ranges from 97.75% to 101.76%. The relative standard devivation (RSD) is in the range of -1.67%~-1.95%. The dosage of chromogenic reagent was 1.0 mL. The room temperature was suitable and pH is 8.4. The proposed method is of high accuracy and precision. This method optimized the determination of CO2-3 and HCO-3 in boron-containing brine. The new method provides a new idea and experimental method for the basic research and practical application of brine, has potential to be applied in fundamental research and process development of brine.