In a group of patients (n=18) with primary (n=7) liver cancer high increase in enzyme activities (AST, ALT, AP, gama-GT, 5'NU), billirubin, alpha-1 AT, alpha- and beta-globulins and alpha-phetoprotein, and considerable decrease of albumin and cholinesterase, were established. These disturbances were duo to the weakened biofunction of the liver. All the examined biochemical parameters are of great significance in the differential diagnosis of cancer, prognosis and development of the disease.