We have already reported the first result on the all-particle spectrum around the knee region based on data from 2000 November to 2001 October observed by the Tibet-III air-shower array .
In this paper , we present an updated result using data set collected in the period from 2000 November through 2004 October in a wide range over 3 decades between 10 ^ { 14 } eV and 10 ^ { 17 } eV , in which the position of the knee is clearly seen at around 4 PeV .
The spectral index is -2.68 \pm 0.02 ( stat . )
below 1PeV , while it is -3.12 \pm 0.01 ( stat . )
above 4 PeV in the case of QGSJET+HD model , and various systematic errors are under study now .