This paper dealt with the influence of various factors on As(Ⅲ) and As(Ⅴ) removal using ferruginous manganese ore, including environmental factors (temperature, time, light, pH) and coexisting ions(HCO3-,CO32-,Cl-,HPO42-,SiO32-,SO42-,Mg2+,Ca2+,Fe3+). The comprehensive influence of various factors was also studied in orthogonal experiment. The results showed that the removal efficiency of As(Ⅲ) was up to 90.26%, while As(Ⅴ) was only 79.88%, under the conditions of that manganese ore dosage was 0.1000g per 50ml polluted water, reaction time was 1h, pH was 3.05, the concentration of arsenic was 204.45ug/l. Lower pH could achieve higher removal efficiency. Illumination was little beneficial to the removal efficiency. SiO32-, HPO42-, CO32- and HCO3- could reduce the efficiency, due to competitive adsorption and electrostatic repulsion. The results of orthogonal experiment indicated that SiO32- and HPO42- were the greatest competitors with arsenic for adsorptive sites on the manganese ore, while temperature and time had no significant effect on arsenic removal.