The novel gas-sensing material of Graphene-loaded PdCl₂ was prepared successfully by the facile method without the use of any additive or organic active agent. The morphology of the as-prepared electrode material was consisted of two different morphologies: thin sheets and small particles with the size of several nanometers. In order to investigate its gas properties, it was used to fabricate a whole solid-state planar electrochemical carbon monoxide sensor. The results showed that the sensor has a practical-use level: response time, 10 s; detect of limit, 100 ppb; sensitivity, 63.34 mV/ppm.