A new enzyme electrode for the determination ofL-asparagine is constructed by chemical immobilization ofL-aspartase [E.C. 4.3.1.1] on an ammonia-gas-sensing probe.L-Asparagine was determined over a concentration range of 1.6 × 10−5to 1.5 × 10−3Mwith a subnerstian response of -51 mV/decade. The electrode was stable for more than 30 days. The effect of pH, substrate and metal activator concentrations, amount of immobilized enzyme, and interferents on the electrode response are reported.