Abstract: Disclosed is a method for early diagnosis of liver cancer. The method comprises the steps of:(A) providing a sample obtained from a subject; (B) assessing the expression level of four subtypes of ?-mannosidase genes consisting of MAN1C1 in the sample; (C) comparing the expression level of ?-mannosidase genes in the sample with a normal control; and (D) determining whether the subject having a risk of suffering liver cancer in accordance with the result of step (C); wherein while the MAN1C1 expression level of the sample is lower than that in the normal control, the subject is determined to have a risk of suffering liver cancer. Additionally, while MAN1A1, MAN1A2 and MAN1B1 expression levels in the sample are higher than those in control group, the subject is determined to suffer from liver cancer and has a risk of metastasis. In the future, MAN1C1 can be applied to early diagnosis of liver cancer and metastasis, suppression of liver metastasis, and screening agents for treating liver cancer.