Coupling of ubiquitin conjugation to estrogen receptor degradation (CUE) domain containing protein, a newly discovered ubiquitin binding protein that contains CUE domain, plays an important role in the tumor formation, metastasis and drug resistance. Some researches have showed that CUE domain-containing protein 1 (CUEDC1) is associated with tumor lymphatic metastasis, and CUE domain-containing protein 2 (CUEDC2) is involved in the occurrence and development of solid tumors and leukemia by regulating cell cycle and signaling pathway activity. This review summarizes the CUE domain containing protein structure and the functions in the occurrence, progression, metastasis and drug-resistance of solid tumors and leukemia.