In this paper, the effect of the loess and mud of an inorganic substance dyed on cotton knitting fabrics have been studied The structure and chemical composition of loess and mud was analyzed. And the Far-Infrared emissivity and emission power, colorfastness, anti-bacterial properties cotton knitting fabrics dyed with loess and mud were also evaluated. The structure and chemical composion of loess and mud was almost identical structure and to be alike main components were SiO$_2$, Al$_2$0$_3$ and Fe$_2$O$_3$. The cotton hitting fabrics dyed with loess and mud have good colorfastness and anti-bacterial properties. when the dyed fabrics was after-treated with diphenyl ether, the anti-bacterial property were improved. Far-Infrared emissivity and emission power cotton knitting fabrics dyed with loess and mud have very good.