This is a randomized, open-label, controlled, multicenter Phase III study to evaluate the effectiveness and safety of IBI310 combined with sintilimab and sorafenib in patients with locally advanced or metastatic HCC who have not previously received systemic therapy, are unsuitable for radical surgical resection or local treatment, or have had progressive disease after surgical resection or local treatment.

Inclusion Criteria:

1. Histologically/cytologically confirmed hepatocellular carcinoma, or liver cirrhosis meeting the clinical diagnostic criteria;
2. ECOG performance status score of 0 or 1 point;
3. No systemic antitumor treatment for hepatocellular carcinoma before the first administration;
4. Barcelona Clinic Liver Cancer stage C, or Stage B not suitable for radical surgery and/or local treatment;
5. At least 1 measurable lesion according to RECIST V1.1);
6. Child-Pugh:≤6
7. Adequate organ and bone marrow function.

Exclusion Criteria:

1. With fibrous lamellar hepatocellular carcinoma, sarcomatoid hepatocellular carcinoma, cholangiocarcinoma components in tumor tissues.
2. Have a history of hepatic encephalopathy or have a history of liver transplantation.
3. With clinical symptoms requires drainage of pleural effusion, ascites or pericardial effusion.
4. Central nervous system (CNS) metastasis.
5. Uncontrolled high blood pressure, systolic blood pressure >140mmHg or diastolic blood pressure >90mmHg after optimal medical treatment.
6. Local treatment for liver lesions within 4 weeks.