The synthesis of Mn0.02Sn0.98O2 nanoparticles by gel combustion method. These synthesized Mn0.02Sn0.980O2 nanoparticles were characterised by XRD and SEM. Mn0.02Sn0.980O2 nanoparticles modified carbon paste electrode (MSNMCPE) was developed by known procedure. The surface morphology of MSNMCPE was confirmed by SEM. The determination of dopamine (DA), uric acid (UA) and ascorbic acid (AA) has been studied at MSNMCPE by cyclic voltammetric technique. The MSNMCPE showed very good sensitivity for DA, UA and AA compare to bare CPE. The results suggest that the nature of electrode reaction was diffusion controlled. The low detection limit (LOD) and low quantification limit (LOQ) of DA, UA, AA were detected. The preparation of the modified electrode was easy, renewed by simple polishing gives very good reproducibility, high stability in its voltammetric response and low detection limit for DA, UA and AA.