Abstract: Gelatin-ring experiment is a technique of studying Rayleigh-Taylor instability growth in a cylindrically convergent geometry. The customary measurement is the high-speed photography which is difficult to distinguish the turbulent mixing zone (TMZ). Therefore, the low and middle energy X-ray radiography system was conducted using the commercial flash X-ray tube and home-made camera. The evolutions of the gelatin-rings inner and outer surfaces were clearly observed by X-ray radiography in different time and gelatins concentration，including rebound of inner surface and turbulent mixing. The experimental results show that the process of the gelatin-rings TMZ can be distinguished by X-ray radiography. Therefore, X-ray radiography is an effective diagnostic in the gelatin-ring implosion experiment.