Objective:In order to understand the changing trends of gastric cancer incidence and mortality in early-onset and late-onset in China from 2000 to 2019.Methods:The Global Burden of Disease research data was collected, and Excel and R 4.2.1 softwares were used to examine the incidence rate, mortality rate, and disability-adjusted life years (DALY) of Chinese people from 2000 to 2019, with a focus on gender, age, and year.Results:In 2019, the crude incidence rates were 7.06/100 000 (95% UI: 6.63/100 000-7.59/100 000) and 114.52/100 000 (95% UI: 108.79/100 000-121.63/100 000) for early- and late-onset gastric cancer, respectively. The crude mortality rate for early-onset gastric cancer was 3.29/100 000 (95% UI: 3.11/100 000- 3.50/100 000), while the crude mortality rate for late-onset gastric cancer was 81.88/100 000 (95% UI: 78.15/100 000-86.04/100 000). Additionally, the crude DALY rates for these two types of gastric cancer were 156.48/100 000 (95% UI: 148.82/100 000-165.84/100 000) and 1 750.13/100 000 (95% UI: 1 661.21/100 000-1 852.99/100 000). The standardized incidence of early-onset gastric cancer decreased from 5.49/100 000 in 2000 to 4.76/100 000 in 2019, and that of late-onset gastric cancer decreased from 143.45/100 000 in 2000 to 123.02/100 000 in 2019.The standardized mortality rate of early-onset gastric cancer decreased from 4.16/100 000 in 2000 to 2.18/100 000 in 2019, and that of late-onset gastric cancer decreased from 140.82/100 000 in 2000 to 91.49/100 000 in 2019. The standardized DALY rate for early-onset gastric cancer in 2019 was 105.87/100 000 (95% UI: 87.98/100 000 -125.60/100 000), lower than 198.84/100 000 (95% UI: 179.47/100 000- 219.83/100 000) in 2000. The standardized DALY rate for late onset gastric cancer in 2019 was 1 821.11/100 000 (95% UI: 1 509.42/100 000-2 158.53/100 000), lower than 2 932.52/100 000 (95% UI: 2 665.92/100 000-3 252.60/100 000) in 2000. Conclusions:The standardized mortality rate of early-onset gastric cancer in China showed a decreasing trend from 2000 to 2019. The standardized mortality rate of late onset gastric cancer showed a trend of first increasing and then decreasing. Notably, the incidence, mortality, and DALY of late-onset gastric cancer were significantly higher than those of early-onset gastric cancer during this period. Additionally, male incidence, mortality, and crude DALY rates were higher than female.