A micro-bonding structure including a substrate, a conductive pad, a bonding layer, a micro device, and a diffusive bonding portion is provided. The conductive pad is on the substrate. The bonding layer is on the conductive pad. A thickness of the bonding layer ranges from about 0.2 μm to about 2 μm. The micro device is on the bonding layer. The diffusive bonding portion is between and electrically connected with the bonding layer and the conductive pad. The diffusive bonding portion consists of at least a part of elements from the bonding layer and at least a part of elements from the conductive pad. A plurality of voids are between the bonding layer and the conductive pad, and one of the voids is bounded by the diffusive bonding portion and at least one of the conductive pad and the bonding layer.