Phenothrin is an important insecticidal and acaricidal agent with certain toxicity. It is highly necessary to develop a rapid, sensitive and selective method for phenothrin assay. This article demonstrated a thermal initiation method to prepare molecularly imprinted electrochemical sensor, which selects phenothrin as the imprinted molecule. Some factors affecting the preparation of the molecularly imprinted electrochemical sensor were optimized and its sensing performance was evaluated. The sensor exhibits a high sensitivity and selectivity towards phenothrin.The response current depends on the concentration of phenothrin at the range of 1.0 ~100.0 μmol/L, and the detection limit is 2.0 × 10-7 mol/L. The sensor has been applied to the analysis of phenothrin in the water of Xiangjiang River with a satisfactory recovery rates ranging from 95.62% to 103.19%