Abstract: This paper theoretically discusses the physical processes taking place in high gain laser fusion driven bysoft x-ray radiation especially implosion dynamics of capsules.For this purpose,the authors suggest a configuration of target and estimate some important characteristics,including efficiencies,environmental temperature of capsule,fuel compression and hot spot ignition etc.,In addition,the paper emphasizes three major harmful effects which have to be controlled for successful performance,that is,asymmetry of implosion,mixing,and hydrodynamic instabilities.