This paper reports that the K x-ray spectra of the thin target 47Ag,48Cd,49In and 50Sn were measured by an HPGe semi-conductor detector in collisions with 84.5 MeV 6C4+ ions.Our experiment revealed the Kα x-ray energy shifts were not obvious and the Kβ1 x-ray energy shifts were about 90~110 eV.The simple model of Burch et al has been previously used to calculate the K x-ray energy shifts due to an additional vacancy in 2p orbit.The present work extends the model of Butch to calculate the x-ray energy shifts of multiple ionized atoms induced by heavy ions with kinetic energy of MeV/u.In addition to our experimental results,many other experimental results are compared with the calculated values by using the model.