Objective: To investigate trends of mean age of diagnosis for liver cancer during 2000 to 2014, which may provide basic information for making feasible cancer prevention strategies. Methods: Based on the continuous cancer incidence data from 22 cancer registries of China between 1 January 2000 and 31 December 2014, the incidence by birth-cohort (year of birth between 1925 and 1994) and age specific incidence rates were calculated. The incidence of different age groups were also calculated. World Segi's population was used for age standardization. The liner regression model was applied to analyze the changing trend of mean age of diagnosis. Results: In 2014, the incidence rate for population with 80 years older and above was 108.21 per 100 000, whereas the rate for population at 30-39 years old was 5.09 per 100 000. But the mean age of diagnosis for liver cancer showed an increasing trend from 2000 to 2014. For male, it had increased from 58.80 to 62.35 (t=18.70, P<0.001) . For female, it had increased from 64.02 to 68.99 (t=20.50, P<0.001) . After age standardization, the mean age of diagnosis still showed increasing trend. Meanwhile, the proportion of liver cancer in people above 70 years old was 25.05% in 2014, which was higher than that in 2000 (22.49%). Conclusion The mean age of liver cancer incidence was increasing during 2000-2014.