Nowdays,  iron  nanoparticles  due  to  their  unique  characteristics  are used  in  all  of  sciences  and  technology.  These  nano  particles  due  to their  electrical, magnetic,  optical  and  catalytic  properties  and  having high  area  and  activity  that  is  promped  by  their  small  size  and most importantly  many  scientists  from  the  entire  world  are  interested  in their  low cost production. In  this project we used method of  reduction in  the  liquid  phase  for  synthesis  of  iron  nano  particles.  Unlike synthesis  so  far  has  been  done  and  they  used  different  kinds  of surfactants  and  capping or  they used  starch  for  stabilization, we  used chelating  agent  diethylene  triamine  penta  acetic  acid  (DTPA)  for increasing  the  stability  of  iron  nano  particles  for  the  first  time  in  the world.  Ammonium  iron(II)  sulfate  were  used  for  make  iron  nano particle and Sodium borohydride was used  for  reduction. This method not  only  was  simple  and  cheap  but  also  didn’t  need  special instruments. Also determining  of  structure,  size, particles  distribution and  surface morphology of  this nano particles we used  the analysis of FT-IR, XRD  and SEM  that  all  of  them  showed  the  synthesis of  zero valent  iron  nanoparticles, metallic  iron,  has  been  done  correctly. The average  of  synthesis  of  zero  valent  iron  nano  particles  is  18  nm  and crystal structure of nano particles was designed by using vertical nano lab  software.  Finally,  we  studied  opration  Removal  of  Radioactive Uranium From groundwater by using iron nanoparticle.