Abstract: The relationship between Leymus chinense and AM （arbuscular mycorrhizal） fungi in different salinities of Songnen alkaline grassland was investigated in this study, the roots of Leymus chinense from low salinity, middle salinity and high salinity were gathered respectively. Using microscopy techniques, arbuscular, vesicles,and other forms of mycorrhizal structure type were observed after Trypan-blue staining and producer. Results showed that AM fungi colonized all Leymus chinense in different salinitie, among which middle salinity got the highest colonization rate, infection intensity, vesicular abundance and arbuscular abundance of 100%,31.78% and 76.25%,while high salinity got the lowest colonization rate, infection intensity, vesicular abundance and arbuscular abundance of only 90%,27.15%,16.90% and 57.74%.There were also significant differences on the colonization of Leymus chinense arbuscular mycorrhizal in the same salinity （P〈0.05）. The AM type of Leymus chinense was A-type in low salinity and middle salinity, while the AM type of high salinity was P-type.