Abstract: Copper alloy contains Pb, Sn, Zn, Ni and other elements, whose distribution and concentration on the surface have important influence on its behavior. As an advanced method for surface analysis of solid samples, time of flight mass spectrometry (TOF-SIMS) has remarkable characteristics of high spatial and mass resolution, and high sensitivity in elemental and isotopic measurements over a wide mass range. In situ analysis of copper alloy surface elements of GBW02137 and GBW02140 samples was implemented by TOF-SIMS, including surface elemental mapping and relative concentration measurement. A pulsed primary ion beam with 5 μm spot size and 30 keV energy was used to bombard the mixed solid alloy samples within a 500 μm×500 μm region, so as to provide complete surface elemental mapping of Cu, Pb, Ni, Sn and Zn elements on copper alloy surface. After being fixed by epoxy resin, the samples were polished and gilded on its surface in order to achieve a surface roughness smaller than 1 μm. After being extracted and focused, the secondary ions got into the time of flight mass analyzer and were recorded by the detector to form spectral peaks. In order to reduce influence of target-surface charge accumulation on the secondary ion extraction field, an electron gun was used to inject electrons towards the target surface to achieve the purpose of charge neutralization. While mapping the elements, a color bar was used to indicate individual content. A deeper color showed a smaller content, and vice versa. Finally, by standard sample calibration method, the calibration curve was established, and the relative concentrations of ⁶⁴Zn/¹²⁰Sn and ²⁰⁸Pb/¹²⁰Sn in GBW02137 and GBW02140 were measured. Considering the difficulty in direct measurement of content by TOF-SIMS because of matrix effect and mass fractionation, calibration of instrument error was needed by using standard samples. Obvious difference of element content exists in the crack and on the alloy surface spot, especially enrichment for Pb element than others. By the standard sample calibration method to measure the content, for ⁶⁴Zn/¹²⁰Sn, a result of relative error value less than 5.1% and RSD better than 2.5% is achieved; For ²⁰⁸Pb/¹²⁰Sn, although relative error is nearly 27%, a result of RSD better than 5% is also achieved. The reason why relative error of ²⁰⁸Pb/¹²⁰Sn is obviously greater is that there exist incomplete calibration curve and ion productive rate difference between Sn and Pb elements. If a precision, complete calibration curve is established, the accuracy of measurement will be improved accordingly.