A sewing system which can properly arrange stitch loops in a sewn section by automatically stitching knitted pieces with each other without requiring the exchange of a main sewing machine body in accordance with the coarseness and fineness of the stitches and is also suitable for stitching a knitted piece with a fabric. The sewing system (10) is provided with the main sewing machine body (14) equipped with a setting table (15) for fixing objects (21a and 21b) to be sewn, a sewing needle(18), a sewing machine bed (12), and a first servo motor (29) which moves the needle (18) upward and downward , an X-Y table (44) equipped with first and second servo motors (45c and 46c) for moving the main body (14) forward and backward in the X-Y direction, a CCD camera (22) which fetches the picture data on the surface of the object (21b), a memory (56) which stores the picture data of the pattern of marks arranged on the surface of the object (21b), and a controller (55) which calculates the coordinates of stitches (α) to be sewn and the needle (18) by comparing both picture data and commands the main body (14) to sew the stitches (α) by moving the main body (14).