Abstract: The Xiaojiazu iron mining area is located in the intersection part of southern-northern tec⁃ tonic system and north-west structural belt in Sichuan-Yunnan region. The fold fault and structure is devel⁃ oped in the area，so it has favorite ore-forming geological conditions. The article puts great emphasis on discussing the ore-controlling factors and ore genesis，based on the previous geological data，metallogenic geological background and geological characteristics of mining area. This research showed that the mining area developed fault structure，the fault crushing belt between Fuliangpeng section of Heishantou Forma⁃ tion and Dalongkou Formation，and the fault intersection zone are mainly ore-bearing position. The ore�bodies (mineralization) are occurred as vein-like and lenticular output. The main ore minerals are includ⁃ ing ironstone and magnetite. Besides，the ore minerals including ironcored mica，pyrolusite and pyrite. and gangue minerals are including quartz and barite，which developed as cryptocrystalline structure，nee⁃ dle-like morphology structure，laminar structure and resorption texture. The Xiaojiazu iron deposit are strictly controlled by stratum lithologic and fault structure，and the faults provide migration channel and host space for deposit. Generally，the faults in mining area have the most significant affection to Xiaojiazu iron deposit. The ore genesis of Xiaojiazu iron deposit is belongs to metamorphic-hydrothermal type，and the structure intersection and typical surrounding rock alteration can be regarded as important ore-pros⁃ pecting marks.

Key words: structural ore-control, deposit genesis, iron deposit