The purpose of this study is to investigate the dyeability of silk fabrics with Humulus japonicus (Hwansam) extract which is a kind of weeds that grows wild in the suburbs. In the research, the general extract method was conducted with the extract from fresh herb of root-removed Humulus japonicus while we investigated the optimal dyeing conditions and dyeability depending on the changes of the kind of mordants, methods and temperature. The functional properties such as antibacterial activities, deodorization and UV protection were also reviewed. The ideal output, as a result, was shown at 100% of dye concentration, $90^{circ}C$ of dyeing temperature and 40 minutes of dyeing time while in terms of dye uptake depending on the kind of mordants and methods, it was found that among four mordants of $SnCl_2$, $AlK(SO_4)_2$, $CuSO_4$, and $FeSO_4$ post-mordanting with $FeSO_4$ showed the best result. Color fastness to washing, dry cleaning and rubbing was found strong at grade 4-5 and the grade to light was as good as 3 while to perspiration was good at 4-5 as well. In aspects of functional properties, it showed excellent results of 99% deodorization rate, 98% UV protection rate and 99.9% bacterial reduction against Staphylococcus aureus.