Objective To find out the morphological regularity of root canal in the primary tooth． Methods Through transparent specimen of a set of deciduous teeth，the shape of root canal was observed under stereomicroscope． Results Among the deciduous anterior teeth, 92% were single canal except for one single-double mixed canal. Maxillary deciduous molar had 3 canals and mandibular deciduous molar had 4 canals, lateral canal and anastomosis between the root canals were popular in deciduous molar. Conclusion Deciduous root canal morphology is simple in anterior teeth and comparatively complex in molar．
