Disclosed is an apparatus for tightening a top of a foot in a leisure sports boot having a sole forming the bottom of the boot; a boot upper rim forming the top end of the boot and having a U-shaped front surface; a boot upper being extended between the sole and the boot upper rim, and consisting of an outside upper forming an outer appearance and an inside upper adhered to a foot; a top of foot protection upper installed inside the U-shaped boot upper rim; and a tightening band tied between the boot upper rims in a zigzag shape outside the top of foot protection upper, the apparatus includes a top of foot tightening means installed inside the top of foot protection upper, for compressing the top of the foot to the sole, a wire passing through the top of foot tightening means, and pulling the top of foot tightening means to the top of the foot so that the heel can be fixedly adhered to the sole, and a wire fixing device connected to both ends of the wire, for selectively pulling or releasing the wire.