Two samples of preschool children's representation and understanding of written number symbols was examined in two time points in one academic year. About 40% of Chinese four year olds (mean=4:7) were able to use conventional number symbols to represent the quantity of ten, on average. The majority of these children (85%) could represent written number symbols at the age of five (mean= 5:4). The characteristic of Chinese children's representation of written numerals was similar to that of British children. However, Chinese four year olds' ability to represent written number symbols seemed better than that of the British group of five year olds; and the performance of Chinese five year olds was more advanced than that of British six and seven year olds. Children's ability to represent written number symbols closely relates to their cardinal concept. The performance of children in a university-affiliated childcare center was better than that of the center serving working-class families.