To provide a printing apparatus which prevents occurrence of register dislocation even when water content of printing paper is changed.

The water content of the printing paper to be used is measured by a water content measuring means 17. Quantity of positional dislocation is measured in advance in relation to the elongation of the printing paper occurring corresponding to the water content, and the quantity is stored in a table memory 24. A positional dislocation forecasting means 20 forecasts the quantity of positional dislocation from the measured water content in comparison with the table memory 24. An image recording position correction means 21 and an image size correction means 22 adjust an image recording position and an image size in advance corresponding to the quantity of positional dislocation to be forecast.