This is an open-label, muticenter phase II study to evaluate the efficacy and safety of QL1706 monotherapy or in combination with bevacizumab and XELOX as first-line treatment of unresectable advanced or metastatic CRC.

Inclusion Criteria:

• 1. Subjects participate voluntarily and sign informed consent.
• 2. Age ≥ 18 and ≤ 80 years old, male or female.
• 3. Histologically confirmed unresectable locally advanced or metastatic adenocarcinoma of the colon or rectum.
• 4. At least 1 measurable target lesion according to Response Evaluation in Solid Tumors (RECIST 1.1).

Exclusion Criteria:

• 1. Diagnosed additional maliganancy within 5 years with the expection of curatively treated basal cell carcinoma of the skin, squamous cell carcinoma of the skin,curatively resected in situ cervival or non-muscle invasive bladder cancers.
• 2. Presence of brain metastases (asymptomatic brain metastases or symptomatic brain metastases who are stable at least 4 weeks, were allowed to be enrolled).
• 3. Has active autoimmune disease that has required systemic treatment in past 2 years.
• 4. Significant cardiovascular disease.