Objective To explore the differences in volatile flavor profiles and discriminate odor characteristics among four kinds of commercially available fermented soybean paste.Methods A comprehensive analysis of the differences in volatile flavor profiles and odor characteristics of four types of fermented soybean paste is conducted by sensory profile, electronic nose, and gas chromatography-ion mobility spectrometry (GC-IMS).Results The main volatile organic compounds (VOCs) in the four types of Northeast Chinese fermented soybean paste are esters, acids, aldehydes, ketones, and heterocyclic volatiles such as pyrazines, furans, and pyrroles. Sour and putrid aromas are the core odors contributing to the "pungent odor" of fermented soybean paste. CJ1 exhibits a more intense and irritating "stinky" odor, CJ2 demonstrates a more layered aroma profile, CJ3 shows a more harmonious aroma, and CJ4 has a milder pungent odor with more pronounced, softer, fresh, and floral aromas. Significant differences in odor characteristics are observed among different fermented soybean paste types.Conclusion The combination of sensory profile, electronic nose, and GC-IMS can effectively distinguish and discriminate the volatile flavor characteristics of the four commercially available fermented soybean paste types.