[Purpose]To estimate the trends in disability-adjusted life years(DALY)caused by gastric cancer(GC)in China from 2000 to 2021.[Methods]Using data from Global Burden of Disease 2021,the DALY and age-standardized DALY rates of gastric cancer from 2000 to 2021 in the Chinese population were analyzed.An age-period-cohort model was used to evaluate the average annual percentage change(AAPC)in DALY rates from 2000 to 2021 in China,and to compare with those in the world,Japan,Korea,and the United States of America.We analyzed the changes in GC DALYs associated with population aging,population growth,and age-specific DALY rates from 2001 to 2021 using a decomposition method,by taking data in 2000 as a refer-ence.[Results]In 2021,GC DALY in the Chinese population were 1 064.21×104 person-years,accounting for 46.70％of the global GC DALY and 14.94％of all cancers DALY in China.The DALY in those aged ≥65 years old accounted for 49.97％.From 2000 to 2021,the total GC DALY in the Chinese population decreased by 4.59％,and the age-standardized rate decreased from 959.29/105 to 501.26/105.From 2000 to 2021,similar decreased trends were observed in China and Japan,with AAPC being-3.58％and-3.72％,respectively.A higher decreased trend was observed in Korea,whereas relatively modest decreased trends were observed in the global levels and in the United States of America,with AAPC being-5.04％,-2.79％,and-1.48％,respectively.From 2000 to 2021,age-specific DALY rates and population aging accounted for the largest decrease and increase in GC DALY.The changes in GC DALY attributed to these two fac-tors were-14.84％(-760.41×104 person-years)and 9.65％(494.56x104 person-years),respectively.[Conclusion]The disease burden of GC in China decreased in the past 20 years.GC DALYs at-tributed to rapidly increased population aging,and population aging has become the first driving factor for the DALY increase in China.The coverage of GC screening population and the inter-vention measures of population aging should be strengthened.