Located in the west of Xiangshan area, the Julong'an uranium deposit has undergone strong chloritization. Based on detailed field investigation and indoor petrographic observation, the authors studied the production state, association relation and chemical composition by applying the electron microprobe technology to the drill hole samples and investigated geochemical features of the chlorite deposit and its relationship with uranium mineralization. Some conclusions have been reached: ① There are four types of chlorites: chlorite from biotite alteration, chlorite from feldspar alteration, colloidal chlorite and uranium-associated chlorite; ② The major chlorites in the deposit are chlorophaeite and brunsvigite, with a small amount of chamosite. The temperature of chlorite varies from 190.5 to 269.9℃, with an average of 224.5℃, suggesting a medium and low temperature condition; ③ The chlorite deposit was formed in a relative reduction environment, with the two formation mechanisms being dissolution-precipitation and dissolution-migration-precipitation; ④ The process of chloritization changed the physical and chemical properties of surrounding rocks and accelerated uranium activation and preenrichment.