Milan criteria: single tumor diameter not more than 5 cm, more frequent tumors not more than 3 and maximum diameter not more than 3 cm, no large vessel invasion, no lymph node or extrahepatic metastasis. UCSF criteria (University College of San Francisco): single tumor diameter not more than 6.5cm, number of tumors not more than 3 and maximum tumor diameter not more than 4.5cm, cumulative tumor diameter not more than 8cm, no large intrahepatic vascular invasion, no extrahepatic metastasis.