We have determined Li abundances for eleven metal-poor turn-off stars , among which eight have [ Fe/H ] < -3 , based on LTE analyses of high-resolution spectra obtained with the HDS on the Subaru telescope .
The Li abundances for four of these eight stars are determined for the first time by this study .
Effective temperatures are determined by a profile analysis of H \alpha and H \beta .
While seven stars have Li abundances as high as the Spite Plateau value , the remaining four objects with [ Fe/H ] < -3 have A ( Li ) = \log ( Li/H ) +12 \lesssim 2.0 , confirming the existence of extremely metal-poor turn-off stars having low Li abundances , as reported by previous work .
The average of the Li abundances for stars with [ Fe/H ] < -3 is lower by 0.2 dex than that of the stars with higher metallicity .
No clear constraint on the metallicity dependence or scatter of the Li abundances is derived from our measurements for the stars with [ Fe/H ] < -3 .
Correlations of the Li abundance with effective temperatures , with abundances of Na , Mg and Sr , and with the kinematical properties are investigated , but no clear correlation is seen in the extremely metal-poor star sample .