1. A tape printing system which forms a label by capturing a print image to print the print image in a tape, the system comprising: bar code information inputting means for capturing a character string with respect to a bar code image included in the print image; bar code image forming means for converting the character string captured by the bar code information inputting means into the bar code image; print preview displaying means for displaying a print preview of the print image; and display controlling means for displaying a bar code guide which gives a target of a bar code image area while the bar code guide is included in the print preview when the print image including the bar code image is displayed by the print preview.