The invention discloses a marker of PPP1CA for liver cancer diagnosis as well as prognosis detection and application thereof. The marker has the advantages that the expression of PPP1CA in tissues of a liver cancer patient is detected in an immuno-histochemical way through RT-PCR and Western Blot; compared with non-cancer tissues, the expression level and protein level of PPP1CA gene are obviously increased; by utilizing ELISA or an immunochemistry luminescence method to detect the content of PPP1CA in the blood, compared with a common person, the content of PPP1CA in the serum of the liver cancer patient is obviously increased; after analysis indicating, the increasing of expression level of PPP1CA in the tissue or blood sample is closely related to the generation and development of the liver cancer; the 5-year survival period of the liver cancer patient with high expression level of PPP1CA is shortened; the liver cancer can be performed with diagnosis and prognosis judging through detecting the content of PPP1CA in the tissue or blood sample; the marker and the method with higher sensitivity and stronger specificity are provided for the clinical diagnosis and the prognosis judging and treatment.