Abstract:The displaying of bidirectional text in SVG is implemented by Unicode bidirectional algorithm, but bidirectional algorithm cannot automatically generate correct results to be displayed in line with semantics in many cases, so additional settings are required. By analyzing the basic principle of bidirectional algorithm, this paper discusses several aspects of bidirectional text display prone to occur, which includes text direction determining, display positions of special characters, text reordering across tspan elements in text elements, and position changes after display direction setting. According to specific circumstances of each issue and individual differences in different browsers, figure out ways to set correctly by using specific attributes in SVG.