我们利用SDSS DR8的测光和光谱数据研究130<l<230,-30<b<30范围内的盘族恒星的数密度分布和速度分布。可以看到在这个天区范围内南北天的恒星分布是不对称的，其中有两个显著的子结构，北天的子结构距离在1.5-2.5Kpc左右，南天的结构在4-6Kpc处。.我们着重研究了北天的子结构，发现这是一个平行于盘的结构，银盘高度大约是0.4-0.7Kpc。.在CMD上沿着这个结构选光谱，并研究它的速度分布，可以看到它存在与标准的薄盘，厚盘运动学模型有很大偏离的成分，目前我们认为它可能是潮汐吸积造成的星流或者盘上的旋臂。我们期望利用lamost的光谱巡天数据可以对它的成因有进一步的判断。

We map the stellar distribution on hess diagram in the Anti-Center roughly in the boxes 130<l<230 and -30<b<10 and -10<b<30. We restrict our data to brighter stars that means g(turnoff)<18th to rule out halo population. Most of those stars are assumed to be thin disk and thick disk star with exponential distribution. Even so, when we look at the data, we can see "extra components" associated with Newberg et al.(2002)'s anti-center structures both in north and south in scope of all of the longitude in our box that can't be explained by standard thin or thick disk models. The distance of the north one is about 1.5-2.5Kpc, the south one is about 4-6Kpc. The north structure is parallel with the Galactic plane, the height from the plane is about 0.4-0.7Kpc. We selected spectral along the structure on hess diagram, study velocity and metallicity distribution. The structure might be stellar stream or sprial arm on the disk. We expect to study it further with lamost data.