Conventional production process of magnesium alloy strips involves many steps, including multi-hot rolling and multi-heat treatment, which is time-consuming and needs high energy cost. By use of thin strip casting, magnesium alloy cast strip with a thickness of less than 8mm can be produced and then rolled to the strip of the needed thickness, which is a short, energy saving and high effective process. In this paper, development of magnesium alloy strips prepared by single and twin roll casting has been summarized. Existing problems have been discussed and its development trends pointed out. Magnesium alloy strips prepared by single roll casting are suitable for Mg-based functional materials but not for structural materials because of low quality or high cost. Horizontal twin roll casting of magnesium alloy, based on aluminium alloy thin strip casting, has been industrialized in Australia and is close to industrialization in China. Vertical twin roll casting of magnesium alloy, based on steel thin strip casting, can reach a speed of more than 30m/min and higher productivity, but the process stability is lower and its research and development is just beginning. Horizontal twin roll casting should be developed for the thicker cast strip, more than 4mm thick, while vertical twin roll casting for the thinner, less than 4mm.