Abstract: In order to explore the mechanism of coal spontaneous combustion and reduce the risk of coal spontaneous combustion in storage and transportation,a tube furnace was used to simulate the low-temperature oxidation process of coal storage and transportation.The evolution law of pore structure of low-rank coal was analyzed by low-temperature nitrogen adsorption-desorption method.The results indicated that the most of holes of the Santanghu coal was similar to neck bottle and ink bottle. And there were also some cylindrical holes and slit flat holes.The critical pore size of Santanghu coal were around 1.8nm, 6.8nm and 9.3nm. With extending oxidation time, the pore roughness and the volume of mesopore and micropore increased. The percentage of pore volume increase was the largest.The transformation of pore structure of Sandanghu coal was be divided into three stages by oxidation temperature.The specific surface area, mesopore and micropore increased before 80℃. The specific surface area and pore volume continued to increase between 80℃-110℃. The pore volume and specific surface area of Santanghu coal reached the largest at 110℃. The pore volume of micropores increased the most.Comparing with the raw coal, the pore volume of micropores increased by 45.83 percentage points and the specific surface area increased by 61.99 percentage points.The specific surface area , micropores and mesopore decreased between 110℃-170℃.