Abstract:  In order to investigate the flotability law of barite，the surface chemical characteristics of barite crystal cell and surface（001）were characterized by CASTEP module in Materials Studio software. Firstly，the structure of the barite cell was optimized. Based on the comparison with the actual cell parameters of barite，it was determined that GGA-WC was selected for the exchange correlation functional，k point was 4×3×4 ，and suitable plane wave cut-off energy was 530 eV. Then，Surface（001）was created based on the optimized barite cell， its Mulliken charge population，and surface energy were calculated. Results showed that the length of Ba-O bond is longer and that of S-O bond in barite cells，so it is conclud? ed that the energy of Ba-O bond is larger and that of S-O bond and the breaking probability of Ba-O bond is higher. By analyzing the density of state and Mulliken charge of each atom on surface（001），the Ba²⁺，-O^- ions can be determined as major chemically active sites on surface（001）. The study on the surface gene characteristics of barite crystal cells can provide reference for the study on the mechanism of flotation reagents and barite.

Key words: Barite, CASTEP, Surface chemical properties, Mineral crystal lattice