Objective To observe the effects of treadmill exercise on learning, memory, and expression levels of inflammatory cytokine interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and nerve growth factor (NGF) in the hippocampus of type 1 diabetic rats. Methods Forty-four adult male Sprague – Dawley rats were randomly divided into control, exercise, STZ, and STZ exercise (STZ+E) groups ( n = 11). A rat model of type 1 diabetes was established by STZ intraperitoneal injection. Exercise and STZ+E groups were subjected to 8 weeks of treadmill exercise. Subsequently, learning and memory were evaluated by Y maze test, IL-6 and TNF-α levels were measured by enzyme-linked immunosorbent assay, and NGF expression was detected by immunohistochemical staining. Results Compared with the control group, STZ group rats exhibited significantly increased standard training times and error times in 30 trials ( P<0. 01), IL-6 and TNF-α were levels significantly increased and the number and area of NGF expression in hippocampal CA1, CA3, and dentate gyrus was decreased (P< 0. 01). Treatment of STZ-induced diabetic rats with exercise improved STZ-induced declines in learning and memory and significantly decreased TNF-α expression ( P< 0. 05). However, hippocampal IL-6 expression in STZ+E group rats was not significantly different (P> 0. 05), and NGF expression in the hippocampus CA1, CA3, and dentate gyrus was significantly upregulated (P< 0. 05). Conclusions Treadmill exercise can improve the learning and memory ability of type I diabetic rats by enhancing NGF expression and anti-inflammatory abilities in the hippocampus.