Soil available nitrogen is a small but crucial component in the nitrogen pool, as productivity in ecosystems is closely linked to nitrogen availability. Since the world's first Industrial Revolution, global warming has increased and nitrogen deposition has increased; therefore, there is a strong focus on soil available nitrogen. To study the short-term response of soil available nitrogen to climate change (warming, nitrogen deposition), we conducted an experiment in four micro-plots planted with young Cunninghamia lanceolata in a mid-subtropical region, which was subjected to experimentally increased soil temperature (W, +5℃) and inorganic nitrogen concentration in artificial precipitation (control[CT], 0 kg hm^-2 a^-1; low nitrogen addition[LN], 40 kg hm^-2 a^-1; and high nitrogen addition[HN], 80 kg hm^-2 a^-1) by using NH₄NO₃. Soil available nitrogen was measured monthly by using ion exchange resin bags. After one year, the results showed that soil available nitrogen concentrated primarily in the summer and winter, and nitrate nitrogen was the main form of available nitrogen. Increasing the soil temperature significantly increased the soil available nitrogen content (P < 0.05). In addition, the soil available nitrogen content was related to monthly air temperature and rainfall. Overall, nitrogen deposition significantly increased the soil available nitrogen content (P < 0.05). Under low nitrogen treatment, soil available nitrogen content increased significantly in most months; under high nitrogen, soil available nitrogen was significantly higher every month than that in the control treatment. With the combined treatment of increased soil temperature and nitrogen deposition, the soil available nitrogen content increased significantly each month, more than that by either increased temperature or nitrogen deposition alone. This indicated that increased soil temperatures and nitrogen deposition had a combined effect on soil available nitrogen content. Therefore, increased temperature and nitrogen deposition, individually or combined, increased soil available nitrogen content considerably, and thus could provide plants with sufficient nitrogen for productive growth.