Objective To explore the method of radiological diagnosis of early attacking congenital syphilis. Methods Seven cases of early attacking congenital syphilis of bone were retrospectively analyzed, diagnosed serologically, and were taken X-rays of the long bones. Results Bone radiographs abnormalities were identified in 6 of 7cases. Five cases suffered periotities, six cases metaphysitis, and three cases combined with diaphysitis. Seven cases had swollen soft tissue. The vertebraes, craniums and epiphysitis were not found abnormal in 7 cases. Diffusion, multiple and symmetric metaphysitis, periosteitis and osteitis were the radiological characters of congenital syphilis of bone. Conclusion Radiography can affirm the diagnose of early attacking congenital syphilis and definite the arrange and depth. Radiographs of the extremities should be routinely taken in suspected infants.