A fast response electrochemical ammonia sensor with open structure is designed and fabricated. The electrolytic cell of electrochemical sensor is prepared by co-firing method. The miniaturization design of electrochemical ammonia sensor is realized. Ceramic porous layer is prepared by screen printing to immobilize electrolyte. The porous gold electrode is prepared as catalytic electrodes

which is benefit to diffusion of ammonia on the electrode and increases response speed of ammonia sensor. Room temperature ionic liquid is used as electrolyte to solve the problem that the electrolyte of the electrochemical gas sensor dries easily

and prolongs the service life of the sensor. An electroc

hemical workstation is used to analyze on response characteristics of the sensor. Response time τ90 is 17 s

detection range of（ 0

100） × 10-6

precision is prior to ± 1. 5 % FS.Experimental result shows that the electrochemical ammonia sensor designed has the characteristics of fast response and high measurement precision.