In this study, we have investigated the difference between the thermal bonding behaviors of mono-component and sheath-core nonwoven fabrics used as hot-melt adhesives. The difference between the manufacturing processes and the melting points of the nonwoven fabrics lead to a difference in their thermal bonding behavior. This was confirmed through image analysis by observing the change in the thermal shrinkage and the pore size ratio with temperature. The difference in the behavior of the fibers is also explained by dynamic mechanical analysis. The analysis of the thermal bonding mechanism of the hot-melt nonwoven fabrics can be used as a supporting data for their manufacturing process in order to improve the performance of the hot-melt adhesives and the design adhesion strength.