The early Yanshanian granites related to tungsten and tin deposits in Nanling region have been considered to be biotite granite, monzogranite, albite granite etc. However, microscope and electron microprobe analyzes of the granite related to tungsten mineralization in Yaogangxian, Shizhuyuan, Xitian, Dengfuxian, Limu and Meiziwo show that all the feldspars of the granite consist of K-feldspar and albite(An5), which suggests that the name should be alkali feldspar granite. The albite of greisen inclusions in the alkali feldspar shows the character An 3. There is no obvious vertical regular variation or zoning of the compositions of the albite and granite within the depth range of 1 000 m. The An value of the albite in alkali-feldspar granite could be used as an indicator for evaluating granite in search for W-Sn mineralization, because the value is obvious lower than that of barren granite.