By use of vacuum organic adsorption and infrared spectrometry, the authors studied the characters of vacuum organic adsorption of hexane, ether and pyridine (their dipole moments are very different: hexane is 0, ether is 1.16 and pyridine is 2.19) by several kinds of fibrous mineral dust and changes of surface groups. The study found that the adsorbability of fibrous mineral dusts to organic reagents are not completely directly proportional to the dipole moments of organic reagents. Clay mineral dust has stronger adsorbability to organic reagents (such as hexane) with a smaller dipole monent, and fibrous mineral dusts have stronger adsorbability to organic reagents (such as pyridine) with a bigger dipole moment. Most of fibrous mineral dusts do not possess the ability of detaining the adsorbed molecules. But the adsorption of some fibrous mineral dusts to hexane is chemical adsorption, and there appear 1262~1267 cm-1and 1311 cm-1new IR bands after desorption. These bands should be IR bands of -SiCH3bonds which were formed after chemical adsorption took place between several kinds of mineral dust and hexane. This paper discusses the changes of surface groups of fibrous mineral dusts after adsorbing organic reagents, especially those of surface OH and surface Si-O-Si.