High temperature superconducting system Bi2Sr2Ca(n-1)Cu(n)O(2n+4+?) n=2,3,4 was prepared by using solid state reaction in oxygen. The nominal composition (n) has major effect on the critical temperature of superconductor compound. The sample prepared with n=2 has critical temperature Tc=104 K, meanwhile the sample prepared with n=4 has critical temperature Tc=86 K, however, the sample that was prepared with n=3 has a maximum critical temperature Tc=110 K. High temperature superconducting system HgBa2Ca(n-1)Cu(n)O(2n+2+?) n=2,3,4 was prepared by using sealed evacuate Quartz tube. The sample prepared with n=2 has critical temperature Tc=118 K, meanwhile the sample prepared with n=4 has critical temperature Tc=122 K, and for sample that was prepared with n=3 has a maximum critical temperature Tc=126 K
