Abstract: The characteristic flavor compounds in five types of sour bamboo shoots from northern Guangdong were analyzed using ultrasonic-assisted solvent extraction-gas chromatography-mass spectrometry (UASE-GC-MS), odor activity values (OAVs), and the 3-AFC method. Principal component analysis (PCA) was applied to compare differences among fermentation processes. A total of 78 volatile compounds were detected, including 16 alcohols, 7 phenols, 9 aldehydes, among others. Thresholds were determined for 14 compounds using the 3-AFC method, and their OAVs were calculated. Sixteen compounds had OAVs ≥ 1, among which p-cresol (The highest OAV among the five samples was 20951.30, and the lowest was 2153.03), decanal (The highest OAV among the five samples was 241.44, and the lowest was 45.40), and 1-octen-3-one (The highest OAV among the five samples was 1958.36, and the lowest was 614.59) showed the highest OAVs and were identified as key flavor compounds. PCA indicated that the sample fermented in large tanks (SGNX-D) had the highest total flavor content (7264.74 μg/g), with its distinctive flavor associated with compounds such as ethyl palmitate, decanal, and phenol. Moreover, this study revealed for the first time the essential role of decanal (highest OAV among aldehydes) and ethyl cinnamate (only ester with OAV > 10) in enhancing the complexity of the flavor profile of sour bamboo shoots.