In order to examine the pre-treatment effect of crab shell on Pb^2+ removal by crab shell in aqueous solution, acid and alkali pre-treated crab shell were used. Electron microscopy techniques such as TEM(transmission electron microscopy) and SEM(scanning electron microscopy), and EDX(energy dispersive X-ray) and FTIR(Fourier transform infrared) spectrometry techniques were used to investigated crab shell was much lower than that by untreated crab shell because of the decrease of CaCo_3 from the crab shell, However, the Pb^2+ removal by alkali pre-treated crab shell increased compared to that by untreated crab shell. The results were confirmed by TEM, SEM, EDX and FTIR.