Space debris is a major problem for all the nations that are currently active in space.Adopting high-precision measuring techniques will help produce a reliable and accurate catalog for space debris and collision avoidance.Laser ranging is a kind of real-time measuring technology with high precision for space debris observation.The first space-debris laser-ranging experiment in China was performed at the Shanghai Observatory in July 2008 with a ranging precision of about 60-80 cm.The experimental results showed that the return signals from the targets with a range of 900 km were quite strong,with a power of 40W (2J at 20 Hz) using a 10ns pulse width laser at 532 nm wavelength.The performance of the preliminary laser ranging system and the observed results in 2008 and 2010 are also introduced.