Thermoelectric properties of orthorhombic or rhombohedral GeSe have attracted great attention recently,with the rise of its structural analog SnSe.However,the p-type cubic GeSe with higher symmetry and higher valence band degeneracy,which might exhibit higher thermoelectric performance,has never been synthesized.Here we report on the successful synthesis of p-type crystalline cubic GeSe by alloying with Sb2Te3 and the spontaneously formed Ge-vacancies.An unexpected glass-like temperature independent lattice thermal conductivity is observed in crystalline cubic GeSe,which results from strong phonon scattering by vacancy-induced disorders.Combining the multiple scattering theory and chemical bond analysis,we further reveal the existence of Anderson localization induced by Ge-vacancies.The Anderson localization results in a nearly constant Seebeck coefficient with increasing the carrier concentration.These results provide a general insight towards understanding and improving the thermoelectric properties of thermoelectric materials with vacancies and atomic-scale disorders.