The race with the most population in the world is the Han Chinese, which makes up 18% of the worlds population. There is an estimated 1.4 billion Han Chinese in the world, and in mainland China, they make up 92% of the population. However, it is important to note that race and ethnicity are complex and often contested categories, and population data can vary depending on how they are defined and measured. It is also worth noting that population size and growth are influenced by a variety of factors, including birth rates, death rates, migration, and government policies.