Abstract: Profound understanding of coke molecular structure and the essence of gasification reactivity is the key of scientific evaluation of coke quality and directional control of coke reaction behavior. Taking 16 kinds of single coals and 8 kinds of coals used in a coking plant in Shanxi as the raw materials, 24 kinds of coals were prepared using a 40 kg coke oven. The macroscopic composition and mesoscopic structural characteristics of cokes were characterized and analyzed by industrial analysis, elemental analysis, gray composition analysis, porosity analysis and coke optical structure analysis. The carbon-pore-ash properties of coke were investigated by using synchrotron X-ray small-angle scattering （SAXS） and wide-angle X-ray scattering （WAXS） techniques. Based on the macroscopic, mesoscopic and microscopic structural characteristics and the dissolution reaction mechanism of coke, the essential relationship between coke structure and strength/reactivity was analyzed. The results show that the carbon mass content of coke organic matter is 96.29%−99.07%. Ash mass content fluctuates in the range of 9.35%−14.51%. Coke prepared from medium clay coal TB and lean coal CZ is rich in pores from 2 nm to 70 nm, showing clear small-angle scattering. During the coking process of coking coal LL and blending coal BC2, the nanopores are closed or transformed into macroporous structures. During this period, the aromaticity （f_a） increases and the aromatic interlayer spacing （d₀₀₂） decreases, thus forming sharp scattering rings, while the remaining coke samples showed weak scattering rings. The formation and development of coke crack network is caused by volatilization release in the pyrolysis process of low-rank coal. The carbon network structure of high-rank coal breaks under the action of thermal stress. Both of which lead to the decrease of the crushing strength （M40） of coke. The appropriate amorphous structure （high Porod slope） and surface roughness of coke molecules can increase the cross-links between carbon layer units and suppress the slip phenomenon between parallel carbon layers. The fractal dimension （D_S） and aromatic stacking size （L_a and L_c） of coke are the fundamental factors that determine the reactivity （CRI） of coke.