【Abstract】Objective To discuss the value of diagnosis of imperforate anus by joint fistula radiography and magnetic resonance imaging (MRI). Methods 16 children with anal atresia and rectum perineum fistula were examined by MRI, which were compared with fistula radiography scanned after injection of about 20 ml saline through the body surface fistula. 23 children would adopt multiazimuth radiography after adding pressure injecting contrast agent through the colostomy by balloon catheter. Results 16 cases with rectal perineum fistula displayed the position of fistula and classify type by MRI. The accuracy of diagnosis was 100%. It was helpful to display the malformation of lumbosacral region, neural tube and genital tract. 9 cases were discovered connection of fistula abnormal channel by fistula radiography. 23 cases were treated with colostomy radiography. 10 cases showed good about the channel flow conditions of plastic operation. 11 cases were found the abnormal channel before the imperforate anus plastic operation,1 case with the megacolon and 1 case with the colon stenosis. Conclusion Diagnosing the imperforate anus by using lowfield MRI improved scanning methods and fistula radiography can improve the display performance. Colostomy radiography has the important meaning before and after the imperforate anus plastic operation.