Abstract: Portulaca oleracea L was a very valuable source of wild vegetable. It was so high in both nutritional value and medical value that it was considered as one of the most prospective green food in 21 century. Portulaca oleracea L was used a long time ago in China and its biological characters, nutritional value, medical value and exploitation were studied, but the research on its taxonomy and introduction propagation was very poor, even the research on genetic improvement was still blank. In order to develop Portulaca oleracea L fully, it was necessary to strengthen the research on genetic improvement to invent a good variety.