In this study, the possibilities of using the highly basic nano-sized anionite based on the anionite AB- 17 as a modifier of the background electrolyte (BGE) in the capillary electrophoresis (CE) for the separation of inorganic anions was investigated. The influence of the concentration of nano-sized anionite in BGE on the velocity and direction of EOF as well as on the efficiency (N, t.p.) and peaks resolution (R) of inorganic anions was determined. It was established that the addition of the highly basic nano-sized anionite to the BGE (with the concentration of functional groups of nano-sized anionite more than 0.01 mM) leads to the reversal of the EOF. This indicates the dynamic modification of the silica capillary walls by the particles of nano-sized anionites and leads to the better efficiency (up to 600-103 t.p.) and increased resolution of inorganic anions compared to BGE containing conventional cationic surfactant - CTAB. Various on-line concentration technics were applied to decrease the LOD of analytes. The LOD of inorganic anions with UV detection and nano-sized anionite as a modifier of BGE were 8-30 ng/ml in case of field amplified sample stacking and 1pg/ml - 7μg/ml for the electro stacking respectively. Thus, the new method of simultaneous electrophoretic determination of 8 inorganic anions was developed and realized for the quantitative analysis of inorganic anions in urine.