Medium-low temperature magmatic hydrothermal gold deposits are widely distributed and large in scale,accounting for about 65 % of the gold deposits in China,which is the main mineral source of gold in China.In the process of prospecting,different types of deposits correspond to different prospecting methods.The determination of the metallogenic model of deposits can provide theoretical support for prospecting as well as theoretical guidance for mineral exploration and prediction.In view of this,the ontology construction and inference mechanism of medium-low temperature magmatic hydrothermal gold deposits are studied in this paper with reference to prospecting and prediction theory of exploration area.Using Protege ontology modeling software,the ontology modeling of the deposit is completed.Based on the SWRL inference rule language,the genesis type of the deposit is defined by inference rules.A set of ontology inference mechanisms oriented to the deposit type discrimination is designed.The inference is completed with the HermiT inference device.After a lot of experiments,the ontology inference method of the deposit genesis type proposed in this paper has a good application effect in the discrimination of gold deposit genesis types and can be widely used in the discrimination of other types of deposit genesis.