The  voltammetric  behaviorsof Crystal  violet      (CT)  and Ciprofloxacin    hydrochloride      (CPFX) were studied at the conductive carbon paste     electrode.   Results demonstrated   that    in B - R  buffer solution  of pH 4. 5      the two    moleculesdisj)layed non - interfering sensitive electrochemical  resjDonses.    The experiment has  conducted   research     and     optimiza­tion of  such     factors which   influence the detection  as   the buffer   solution    category，pH，accumulation     potential and time. And then a new method for determining residual CT and CPFXwas developed. Tested with half impulsive differ­ential mode，there     was a  linear  relationship   between     the peak currents and the   concentration of     CT    in the range   of 2. 5 X 10 ⁸ ~ 1.325 X 10 ⁶mol/I_J withi a coexistence of CPFX； there was a linear relationship between the peak cur­rents and the concentration of CPFX in the range of 5.0 X 10 ⁸ ~ 4. 85 X 10 ⁶ mol/L with a coexistence of CT. The detection limits    were 10. 5    and  21.2 nmol/L    (5/L   = 3 )，respectively. Satisfactory  results   were obtained  when  the new method   was used    to  measure   CT and CPFXin the real fresh     fishery water   samples with     average recovery   rates of97. 8O and 101. 1O，respectively.  The metiiod exhibits many    attractive       advantages，such      as simple   operation，rapid response，lowcost，and so on. Therefore it is promising for popular application. [ Chinese Fisiiery Quality and Stand­ards， 2015, 5(3) ：27 -33]