Abstract: The root's growing condition can reflect the climatic characteristics and soil status. Existing methods such as excavation, monolith and bisection will destroy the sample and have too much work to do. To track the root's growing addition in real time, this paper introduced a method based on adaptive thresholds and multiscale wavelet transforms, by which we can detect the edge of a root's image that obtained by endoscopy and then mosaic the images extracted from the edge. The method analyses the growing condition of the root automatically without any destroying. Through this system, we can acquire real-time collection and accurately measure the root's physical parameters.