The Ejinhoro Formation (simplified Chinese: 伊金霍洛组; traditional Chinese: 伊金霍洛組; pinyin: Yījīnhuòluò Zǔ) is a geological formation in Inner Mongolia, north China, whose strata date back to the Early Cretaceous period (Aptian/Albian age. Dinosaur remains are among the fossils that have been recovered from the formation.