Abstract: Conducted systematically investigations to the chemical composition，mineral composition，embedded features，grain size，texture and structure of ores from sijiaying Iron Ore Mine. The research result indicated that the available element is Fe；the main components of iron ore content is hematite and magnetite；gangue mineral is quartz primarily，and then mica，hornblende and chlorite；the average grain size is 0.116 mm；the relationship between gangue minerals and iron minerals are mainly adjacent and mosaic structure. Combined with the chemical analysis and the microscopic identification results，it is confirmed that amphibole minerals have a close relationship with magnetic iron. Summarizing the technological mineralogy investigation，the iron ores can be divided into three technological types: easy to disintegrate and easy to selection，easy to disintegrate and hard to beneficiate，hard to disintegrate and hard to beneficiate. The typical characteristics and dressing influence factors have also been analysed for each type.

Key words: Technological mineralogy, Embedded features, Technological types, Dressing influence factors