Abstract:The bioaccumulation and distribution of Ciprofloxacin in carp, Allogynogenetic crucian were assessed with stimulated aquatic microsystem, the same was done for the enzymatic activities in phaseⅠ, Ⅱ metabolisms process of the carp. Results showed that the bioaccumulation and distribution of CPFX in A. crucian exhibited remarkable differences under various exposure ways. The residual concentration of CPFX in visceral and muscle tissues of carp were much higher through feeding exposure than via waterborne exposure. But no matter which way was made, there was same the trend: CPFX were absorbed quickly at initial stages and reached the highest value soon. With the extent of the exposure time, the residue of CPFX in carp decreased gradually. EROD activity was inhibited at the primary period under the exposure of CPFX and then returned to the original level after 45 days of exposure. GST activity in carp was induced under the exposure of CPFX showing a lag response phenomenon and the increase of GST activity displayed in three exposure pathways. GSH content in carp decreased in all treatment groups early and then displayed inducement response and resumed the level before being exposed after 45 days.