A display panel, a display device and a manufacturing method of the display panel are disclosed. The display panel includes: an array substrate and a counter substrate disposed in opposition to each other, and a sealant adhered between the array substrate and the counter substrate; in a peripheral region of the array substrate positioned in opposition to the sealant, there are provided a plurality of thin film transistors, a surface of each of the thin film transistors is covered with a block-like insulating film, and there is depressed region between adjacent block-like insulating films; at the location of the counter substrate corresponding to the depressed region, there is provided a protruding structure. By adopting the scheme, adhesive areas between the sealant and the array substrate and the counter substrate each are greatly increased. Therefore, the adhesion force of the sealant is effectively raised, and the product quality of the display device is promoted.