On the Page Layout tab, in the Page Setup group, click Print Titles.
On the Sheet tab, under Print titles, do one or both of the following:
In the Rows to repeat at top box, type the reference of the rows that contain the column labels.
In the Columns to repeat at left box, type the reference of the columns that contain the row labels.
For example, if you want to print column labels at the top of every printed page, you could type $1:$1 in the Rows to repeat at top box.