We have taken a deep , moderate-resolution Keck/Deimos spectra of QSO , CFHQS2329 , at z=6.4 .
At the wavelength of Ly \alpha , the spectrum shows a spatially-extended component , which is significantly more extended than a stellar spectrum , and also a continuum part of the spectrum .
The restframe line width of the extended component is 21 \pm 7 ( Å ) , and thus smaller than that of QSO ( 52 \pm 4Å ) , where they should be identical if the light is incomplete subtraction of the QSO component .
Therefore , these comparisons argue for the detection of a spatially extended Ly \alpha nebulae around this QSO .
This is the first z > 6 QSO that an extended Ly \alpha halo has been observed around .
Careful subtraction of the central QSO spectrum reveals a lower limit to the Ly \alpha luminosity of ( 1.7 \pm 0.1 ) \times 10 ^ { 43 } erg s ^ { -1 } .
This emission may be from the theoretically predicted infalling gas in the process of forming a primordial galaxy that is ionized by a central QSO .
On the other hand , if it is photoionized by the host galaxy , an estimated star-formation rate of > 3.0 M _ { \odot } yr ^ { -1 } is required .

If we assume the gas is virialized , we obtain dynamical mass estimate of M _ { dyn } =1.2 \times 10 ^ { 12 } M _ { \odot } .
The derived M _ { BH } / M _ { host } is 2.1 \times 10 ^ { -4 } , which is two orders smaller than those from more massive z \sim 6 QSOs , and places this galaxy in accordance with the local M- \sigma relation , in contrast to a previous claim on the evolution of M- \sigma relation at z \sim 6 .
We do not claim evolution or non-evolution of the M- \sigma relation based on a single object , but our result highlights the importance of investigating fainter QSOs at z \sim 6 .