Abstract: Skates attachable to sneakers. The device includes a sneaker body and a lower functional unit (such as an ice-skate unit, a roller skate unit, etc.), assembled with or disassembled from each other. The sneaker body has a sole and a large sole under the sole, and the sole has recesses and a tenon formed in each recess, and one of the tenons has an insert hole in its sidewall. The lower functional unit has plural connect members with mortises engaging the tenons. Each connect member has a stop plate in front of the mortise, with an aperture formed between them for a safety pin and a spring fitted around the pin to fit therein. The safety pin passes through the hole of the stop plate and a lateral hole of the inner wall of the mortise, with its outer end inserting in the insert hole of the tenon.