The ordinate and abscissa of the line chart show the changing trend of variables with time, space and other factors. If line charts are used to describe other types of trends, the meanings of abscissa and ordinate will change accordingly. When drawing a line chart of a paper, the meanings of abscissa and ordinate should be determined according to the variables studied and the research purpose, and the readability and accuracy of the chart should be ensured. The ordinate of a line chart generally indicates the value or proportion of variables, such as sales, quantity, ratio, etc. The abscissa represents time, space or other factors that change with time/space, such as date, season and region.