This study investigates the role of the medial prefrontal cortex (mPFC) and the thalamic nucleus reuniens (Re) in social recognition in male mice. Single-unit recordings and decoding analysis reveal that both mPFC and Re represent different social stimuli, with mPFC showing stronger coding capacity. Chemogenetic inhibition of Re impairs mPFC-Re neural synchronization and social coding in the mPFC. Optogenetic manipulations further demonstrate that the reciprocal connectivity between mPFC and Re is essential for social recognition. Information-theoretic and population decoding methods show that chemogenetic inhibition of Re reduces social information coding in the mPFC. These findings identify a prefrontal-thalamic circuit critical for social information processing and social recognition.This study investigates the role of the medial prefrontal cortex (mPFC) and the thalamic nucleus reuniens (Re) in social recognition in male mice. Single-unit recordings and decoding analysis reveal that both mPFC and Re represent different social stimuli, with mPFC showing stronger coding capacity. Chemogenetic inhibition of Re impairs mPFC-Re neural synchronization and social coding in the mPFC. Optogenetic manipulations further demonstrate that the reciprocal connectivity between mPFC and Re is essential for social recognition. Information-theoretic and population decoding methods show that chemogenetic inhibition of Re reduces social information coding in the mPFC. These findings identify a prefrontal-thalamic circuit critical for social information processing and social recognition.