Objective : To investigate the co-labeling of c-Fos protein expression and oxytocin ( OXT) neurons in related brain regions in mice injected with dexmedetomidine( Dex) by intraperitoneal injection． Methods : 8 －10 week old C57 mice were divided into Saline group and Dex group．The Saline group was intraperitoneally injected with normal saline，the Dex group was intraperitoneally injected with Dex ( 100 μg / kg) ，the control group was giv- en normal saline (Saline group) ，and the experimental group was given Dex 100 μg / kg (Dex group) ．120 minutes after intraperitoneal injection，the brains of two groups of mice were collected by perfusion，and thenfrozen section and immunofluorescence microscopy imagingwere performed. Results : Immunofluorescence c-Fos protein expres- sion in Dex group and Saline group．The results showed that compared with the Saline group，the Dex group had higher thalamotomy in the supraoptic nucleus ( SON) ，ventrolateral preoptic nucleus ( VLPO) ，subfornical organ (SFO) ，solitary tract (SOL) and area postrema (AP) ，and the difference was statistically significant．C-Fos in the locus coeruleus(LC) ，lateral hypothalamic area (LH) ，laterodorsal tegmental nucleus (LDT) ，parabigeminal nu- cleus (PB) ，ventral tuberomammillary nucleus ( TMN) and motor cortex M1 / M2 protein expression decreased， and the difference was statistically significant (P＜0. 05) ．There was no difference in c-Fos protein expression in parathalamic nucleus (PVN) and suprachiasmatic nucleus ( SCN) ．The results of the co-labeling group of OXT neurons and c-Fos protein in the PVN and SON brain regions showed that : compared with the Saline group，there was no significant difference in the co-labeling of OXT neurons and c-Fos protein in the PVN and SON brain regions of the Dex group． Conclusion The immunofluorescence co-labeling experiment shows that Dex can activate sleep- promoting and other related brain regions，and has a certain inhibitory effect on wake-promoting and exercise-relat- ed brain regions，however，it does not affect the co-labeling of c-Fos protein and OXT neurons in PVN and SON brain regions.