A simple and efficient molecularly imprinted (MIP) electrochemiluminescence (ECL) sensor with graphitic carbon nitride nanosheets (g-C(3)N(4)NSs) as emitter was developed for sensitive and selective determination of hydroquinone (HQE). The resulting MIPECL sensor exhibits not only high sensitivity and selectivity to HQE, but also excellent reproducibility and stability, and was successfully applied to detect HQE in water samples with satisfactory results. Owing to easy preparation and low cost, this MIP-ECL sensor has a great potential for development and application.