Abstract: In this apparatus for stretching sewn portions of cloth, comprises a stretching member extends along the feed direction of the cloth in the front and rear of the sewing position of a sewing machine. This stretching member includes an inserting portion which enters into the cloth in the front of the sewing position prior to sewing and a pair of stretching portions for stretching the cloth from both sides with the sewn portion acting as the boundary in the rear of the sewing position. The stretching portions extended backwards in parallel with a predetermined distance between them and the thickness gradually increases towards the rear. A guide member for guiding and shifting the stretched cloth toward the rear extends from the rear end of one stretching portion in the backwards direction with the same thickness as that of the rear end of this stretching portion.