中文摘要：

系自转曲线测定对星系天文学研究有着重要的意义。现己发现，除旋涡星系外，其他类别的河外星系也有自转运动，但自转曲线的特征有所不同。自转曲线研究的内容颇为丰富，如是否存在普适自转曲线，星系团环境对成员星系运动特征的可能影响，星系物质转动速度的垂向梯度问题，以及星系中暗物质的分布等，对上述内容做了相关评述。

英文摘要：

The rotation curve of a galaxy describes how the rotational velocity V（R） of its matter depends on the distance R from the galaxy center, and represents evidence for the mass distribution within the galaxy and can be used for studying its kinematics and dynamics characteristics and inferring its evolutionary history. Both optical and radio observations of rotation velocities within galaxies can be used to derive their V（R）, by using absorption lines such as H and K lines and emission lines such as Ha, HI and CO lines. A brief review of developments in observations and studies of rotation curves of galaxies is given in this paper. Generally speaking, the V（R） curve increases monotonically and steeply in the central region of a galaxy out to a distance Rt of the turnover point, at which the V（R） reaches a maximum value Vmax, and beyond Rt the velocity either remains constant or varies gradually with a small amplitude, which is usually called as the flat rotation curve. The major researches on rotation curves have been done for spiral galaxies. It has been found that the maximum velocity Vmax increases from the late type spirals to early ones, which are of some 300,220 and 175 km.s^-1 respectively for Sa, Sb, and Sc galaxies. Besides normal spirals, galaxies with various Hubble types also show rotations in some way, including barred spiral, elliptical, lenticular and irregular galaxies. Since the 1970s the difference between the matter distribution implied by the luminosity and that implied by the flat rotation curve has been used as strong evidence that galaxies are embedded in extended halos of dark matter, because without such massive dark halos, rotation velocities in the outer regions of galaxies should show the Keplerian falloff. However, some people argue such an explanation for the fiat rotation curve, and believe that the models without dark matter are also able to satisfactorily reproduce the observed kinematics in most cases. Moreover, someone pointed out that there is also a possibi