Selective tungsten chemical vapor deposition (W-CVD) is one of the most attractive technique for filling deep submicron contact hole and via hole for the ULSI application. In this work, we firstly find out the anomalous selective W growth for the contact hole. The tungsten only nucleates from the side ring of the contact hole bottom. Several predeposition treatments prior to W growth can improve this anomalous feature and excellently selective W growth can be achieved. Auger electron spectroscopy (AES) is utilized to investigate the interface of Si/W. A model has been proposed to explain this anomalous selective tungsten growth.