Objective:To investigate the early changes of serum biomarkers in rats with mild blast-induced traumatic brain injury (bTBI) in cabin.Methods:Explosion source in the simulated cabin was detonated by initiator. The bTBI rat models caused by explosion shock wave in cabin were established. A total of 24 adult male Sprague-Dawley rats were divided into normal control group ( n=6) and bTBI group ( n=18), according to the random number table. Rats in bTBI group were subdivided at 3, 24, and 72 h post-blast, with 6 rats at each time point. Shock wave pressure at the rat head was measured during the explosion. At 3, 24, and 72 h post-blast, the general condition of rats was observed. Rat blood was collected by cardiac puncture. Then brains were taken completely and quickly for pathological observation. HE staining was used to observe the changes of neurons in hippocampal CA1 area. The collected serum was tested for levels of biomarkers, including interleukin- 6 (IL-6), neuron specific enolase(NSE), S100-β, alpha Ⅱ-spectrin breakdown product-145 (SBDP-145) and Tau. Results:The maximum peak value of the shock wave pressure curve at the rat head was (818.2±33.3)kPa, and the duration was about 1 000 μs. After the explosion, the activity of the rats decreased significantly, the hair was dull, and the appetite decreased. General observation showed that the brain tissue was obviously swollen, the blood vessels on the brain surface were thickened, and there was a little patchy bleeding, but no obvious brain contusion was seen. HE staining showed that some neurons in the hippocampus CA1 area had apoptosis or necrosis. At 3, 24, and 72 hours post-blast, the levels of IL-6 were (155.3±10.7)pg/ml, (171.3±25.3)pg/ml and (155.6±18.2)pg/ml, all of which were significantly higher than that in normal control group [(116.3±7.3)pg/ml]( P<0.05); the levels of NSE were (12.0±1.0)ng/ml, (11.0±1.0)ng/ml and (11.0±1.2)ng/ml, all of which were significantly higher than that in normal control group [(8.1±0.5)ng/ml]( P<0.05); the levels of S100-β were (71.9±10.7)pg/ml, (58.0±11.5)pg/ml and (56.5±12.2)pg/ml, all of which were significantly higher than that in normal control group [(35.2±2.5)pg/ml] ( P<0.05); the levels of SBDP-145 were (29.4±2.8)ng/ml, (24.5±4.8)ng/ml and (20.7±2.1)ng/ml, and only the level at 3 h post-blast was significantly higher than that in normal control group [(20.9±1.2)ng/ml]( P<0.05); the levels of Tau were (141.4±11.7)pg/ml, (189.5±28.2)pg/ml and (179.1±32.5)pg/ml, all of which were significantly higher than that in normal control group [(97.8±5.9)pg/ml]( P<0.05). Conclusion:The serum levels of IL-6, NSE, S100-β, SBDP-145 and Tau in mild bTBI rats increase in various degrees at early time, which provides a theoretical basis for use of serum markers in the early diagnosis of mild bTBI.