The crystal structure and the dielectric properties of the antiferroelectric solid solution of (1-x)Pb(Yb1/2Nb1/2)O-3-xBa(Yb1/2Nb1/2)O-3(Pb1-xBaxYN) (0 less than or equal to x less than or equal to 0.30) have been studied. The crystal structure is shown to become pseudocubic from the PYN's orthorhombic structure on solutionizing for x >0.5 while the transition shows a normal first-order paraelectric(PE)-antiferroelectric(AFE) behavior increasing x<0.14. The transition temperature gradually decreases with the increasing Ba2+ concentration. In the composition range 0.16 square x square 0.30, a typical relaxor behavior is displayed.