Abstract: Most important characters of plant are quantitative ones. In order to manipulate genes of these quantitative traits, men have been trying for a long time to explain their genetic laws. Development of modern molecular biological technology makes it possible to map and to separate genes of quantitative traits. This article summarizes some fields in quantitative traits for plant, such as population types and their characteristics, methods of mapping quantitative trait loci, researching status of QTL, fine mapping, clone and application of QTL, and furthermore, gives an expectation on QTL research in future.