We,implantologists, have focused on obtaining the initial primary stability during the insertion of dental implants. The primary stability is considered as the most important key of the success of the osseointegration of dental implants. But some cases was success though the lack of the initial stability, and the one is the one stage procedure that was floating and sinked by finger pressure though longer time required. So, I think that the oseointegration woud be succeeded though the absence of primary stability. The primary stability is the physiologic phenomena caused by the screw of implants or the tight fittness controlled by the insertion techniques. I consider it as a active stability caused by implants itself,whereas the passive stability is obtained by others like as natual teeth nearby , temporary implants and cross arch stabilization by other implants though it itself has the lack of stability. Now, I propose that the osseointegration would be succeeded though the lack of traditional primary stability if it is immobilized by passive stability. But it is my hypothesis, so more clinical studies and research will be required. Thank you very much.