Abstract: Plane grating spectrograph is commonly used in the determination of silver (Ag), boron (B) and Tin (Sn) in geochemical samples. In this work, a CCD-Ⅰplane grating direct-reading spectrometer has been successfully developed to replace the two-meter plane grating spectrograph so as to improve the efficiency and quality of analysis. The detection limits of the updating instrument for Ag, B and Sn were 0.013, 0.71 and 0.43 μg/g, respectively. The relative standard deviations (RSDs n=12) were less than 10%.The analytical accuracy was validated by the national standards and the results are in agreement with the certified values.The proposed method can meet the requirements for the determination of Ag, B and Sn in geochemical samples.