Abstract: Alkanes are saturated hydrocarbons in the cuticular wax of plants, which can be used as a marker for determination of dry matter intake and diet selection by grazing ruminants. The concentrations and profiles of alkanes from roughage (introduced and natural Leymus chinensis grassland, maize, and soybean residues), were analysed to provide basic data for research on grazing sheep in the farming-pastoral zone of the Songnen Plain. The n-alkane profiles of forage from grassland and crop residues were different from different species. In the range of C₂₁-C₃₅, the content of odd n-alkanes were more abundant than those of the even n-alkanes. Whole L. chinensis at different growth stages, Echinochloa crusgalli, and Artemisia anethifolia collected in May, Sonchus bracyotus growing in May and August, Setaria viridis, and stems, leaves, and pods of Glycine max and Zea mays crop residues, had the maximum alkane concentration for C₃₁. The concentration of C₂₉ n-alkanes was most abundant in Iris ensata and ear heads of L. chinensis and E. crusgalli in July while A. anethifolia had a maximum alkane concentration for C₂₇ in August.