The primary objective is to explore the efficacy and safety of azacytidine and HAG regimen versus azacytidine for elderly patients with Newly Diagnosed MDS/AML/CMML in China. This is a post-marketing, interventional, multi-center, double-arm, prospective, open-label, randomized controlled study in elderly patients with MDS/AML/CMML in China. Patients will be recruited consecutively from the study sites during the enrollment period. The enrolled patients will be given azacytidine + HAG regimen or azacytidine under the conditions of informed consent and frequent monitoring according to the clinical guideline.

Inclusion Criteria:

• Age ≥ 60;
• Patients with newly diagnoised diseases including MDS/AML/CMML;
• The ECOG behavior status score is less than 3 points;
• Agree to sign informed consent

Exclusion Criteria:

• Patients with a history of sever heart disease;
• Patients with severe organ dysfunction;
• Patients with other malignancies
• Patients who are allergic to the treatment of drug ingredients