An adsorbent,aminated mesoporous silica was synthesizmg via aminopropyl silatrane functionalizing mesoporous silica.The characterization of this adsorbent was investigated by transmission electron microscopy（TEM） and fourier transform infrared spectroscopy（FT-IR）.A new method was developed for the determinaon of trace cadmium by flame atomic absorption spectrometry（FAAS） after separation/preconcentration with the aminated mesoporous silica material as adsorbent.The influencies of various analytical parameters on cadmium extraction,such as pH value,flow rate of sample,type and amount of eluent,adsorption capacity of adsorbent and interfering ions were investigated.The results indicated that cadmium could be well absorbed at pH 7.0 and a sample flow rate of 8 mL/min.After adsorption,Cd（Ⅱ） was eluented with 5.0 mL 2.0 mol/L HNO3,and determined by FAAS.The linear range of Cd（Ⅱ） ranged from 0.6 ng/mL to 20 ng/mL.The limits of quantitation（LOQ） was 0.5 ng/mL,and the enrichment factor for the present method was obtained to be 50.The RSD（n=11） for 10 ng/mL Cd（Ⅱ） standard solution was 0.92%.The spiked recoveries of Cd（Ⅱ） were in the range of 98.8%-104.5%.The modified mesoporous silica demonstrated an excellent anti-interference capacity,and the adsorption/desorption process remained effective for at least twelve consecutive cycles.The method was applicable for the determination of trace Cd（Ⅱ） in environmental water samples with satisfactory results．