The halo structure at high Galactic latitudes near both the north and south poles is studied using SDSS and SuperCOSMOS data .
For the south cap halo , the archive of the SuperCOSMOS photographic photometry sky survey is used .
The coincident source rate between SuperCOSMOS data in B _ { J } band from 16 ^ { m } .5 to 20 ^ { m } .5 and SDSS data is about 92 % , in a common sky area in the south .
While that in the R _ { F } band is about 85 % from 16 ^ { m } .5 to 19 ^ { m } .5 .
Transformed to the SuperCOSMOS system and downgraded to the limiting magnitudes of SuperCOSMOS , the star counts in the northern Galactic cap from SDSS show up to an 16.9 \pm 6.3 \% asymmetric ratio ( defined as relative fluctuations over the rotational symmetry structure ) in the B _ { J } band , and up to 13.5 \pm 6.7 \% asymmetric ratio in the R _ { F } band .
From SuperCOSMOS B _ { J } and R _ { F } bands , the structure of the southern Galactic hemisphere does not show the same obvious asymmetric structures as the northern sky does in both the original and downgraded SDSS star counts .
An axisymmetric halo model with n=2.8 and q=0.7 can fit the projected number density from SuperCOSMOS fairly well , with an average error of about 9.17 % .
By careful analysis of the difference of star counts between the downgraded SDSS northern halo data and SuperCOSMOS southern halo data , it is shown that no asymmetry can be detected in the south Galactic cap at the accuracy of SuperCOSMOS , and the Virgo overdensity is likely a foreign component in the Galactic halo .