Abstract: In an acetate buffer medium of pH 5.2,and in the presence of n-butanol and CTMAB,sensitivity of the color reaction between boron(Ⅲ) and azomethine H was raised about 31%.Absorption maximum of the colored complex was found at the wavelength of 412 nm,where the molar absorptivity was found to be 3.62×104L·mol-1·cm-1.Beer′s law was kept in the range within 1.6 mg·L-1,corresponding to the linear regression equation of A=0.043 57+0.020 72 C (C concn.of B(Ⅲ) in mg·L-1) with its correlation coefficient of 0.999 7.The proposed method was used in the determination of microamounts of boron in lithium carbonate,giving values of RSD′s (n=8) less than 2.0%.Recovery test was performed by standard addition method,and values of recovery obtained were in the range of 99.8%-101.5%.