A biosensor for dimethoate was prepared by exploiting their inhibitory effect on the activity of acetylcholinesterase(AChE).Carbon/Pt sphere material with good chemical stability, large surface area and good conductivity was used to modify the electrode.Compared to a bare electrode, the electron transfer resistance of the prepared electrode is lower,and its peak current is increased by 147.06%.This is ascribed to the larger surface of the Carbon/Pt ball material which could improve theadsorption for AChE and enhance its activity.Under the optimal experimental conditions , the concentration of negative logarithm of dimethoate and inhibition ratio showed a good linear relationship from 1.0×10-9 g/L to 1.0×10-6 g/L.The detection limit was 7.3×10-12g/L(the inhibition rate was 10%).The spiked recoveries for textile samples were in the range of 86.2%-101.7%.The method may provide a new way to fabricate highly sensitive biosensors for the detection of organophophate pesticides in textile.