The Hercynian-Indosinian granitoids in Hongshishan area of the Beishan orogenic belt belong to the calc-alkaline series and have characteristics of is land-arc granitoids. A study of their petrochemical, geochemical and Nd-isotopic characteristics shows that they have the characteristics of “adakite”These rocks have the following characteristics: SiO2＞56％，Al2O3≥15％,Na2O and Sr are high, MgO<3％, Mg#=30.71～59.13, Sr/Y=19.71～72.86, Y<18×10-6（6.0×10-6～14.7×10-6）; no Eu anomaly or only weak negative Eu anomaly can be observed; REE distribution patterns show strong REE segregation and belong to the type of enriched LREE; and there exist very prominent negative Nbanomaly and obvious positive Sr anomaly in the trace element spidergram εNd(t) values are positive ［εNd（t）＝4.09～5.67］, major samples fallinto the area of adakite on (La/Yb)N-YbN and Sr/Y-Y diagrams Therefore, the discovery of the adakitic rock has great significance in the study of Late Paleozoic tectonic evolution and geodynamics and the search for ore deposits in the Beishan orogenic belt of Gansu Province