A serial inkjet printing apparatus is capable of stably printing a preferable image, when a printing medium is released and conveyed from an upstream conveying unit, and when the printing medium is conveyed by only a downstream conveying unit. Specifically, the serial inkjet printing apparatus, which includes the upstream conveying unit and the downstream conveying unit, corrects a conveyance amount of the printing medium by predicting a shift of a printing position due to expansion or contraction of the printing medium, when the printing medium is released and conveyed from the upstream conveying unit, and when the printing medium is conveyed by only the downstream conveying unit.