— We constructed a new model of an olfactory system with expanded integrate and fire neurons to explore its behaviors with external inputs. The model is built in according to the reliable medical and anatomical data about biological olfactory systems. Expanded integrate and fire neurons become synchronized when the external inputs fall in a small range, which is similar to the standard neurons introduced an applied by Hopfield to the olfactory system. We investigate the range of external input currents leading to synchronization for expanded integrate and fire neurons. This feature is used to recognize spatial patterns which represent odorants. Both spatial and temporal patterns exist in the networks.