Abstract: Electrochemical behavior and electrochemical kinetic parameters of LSP at carbon paste electrode (CPE) were investigated by cyclic voltammetry (CV),chronoamperometry (CA),and chronocoulometry (CC).Electrochemical experimental results showed that LSP in 0.10 mol/L PBS exhibited an irreversible electrochemical redox process at CPE,and the oxidation peak potential (E_pa) was 0.956 V.The plots of oxidation peak current versus the square root of the scanning rate for the redox in a potential range of 10~1 000 mV/s were linear,as expected for a diffusion-limited electrochemical process for LSP electrochemical oxidation.Electron transfer coefficient α,diffusion coefficient D,and apparent reaction rate constant k_f were 0.77,2.47×10^-5 cm²/s and 3.46×10^-3 cm/s,respectively.The chang of the oxidation peak current with LSP concentration was examined by Square wave voltammetry (SWV).The oxidation peak current of LSP versus its concentration showed a good linear relationship in a concentration range of 1.0×10^-6~5.6×10^-3 mol/L with a correlation coefficient of 0.999 8 and a detection limit of 5.0×10^-7 mol/L by SWV response.The relative standard deviation was between 1.9%~2.3%,and the recovery was in a range of 98%~102%.The proposed method were applied to the determination of LSP in capsule samples with satisfied results.