Abstract: In order to observe, assay and sample accurately for corn root system growth, our study adopted the maize root pictures obtained from the root monitoring system (SYIAE-01) developed by Institute of Atmospheric Environment, CMA, Shenyang, studied the root digital image based on the digital image recognition technology (IBR), used the method of SIFI and OTSU to compile the root image software, consisted three parts of the image geometric distortion correction, image stitching, image extraction and root area calculation, researched and analyzed the digital image of root obtained by the software. The results showed that: the root image mosaicing, extraction and analysis system based on the Matlab preliminary realized in situ identification of corn root system characteristics, the system could improve the working efficiency of sorting corn root system image, and helpful to calculate the root area.