A wafer structure with a buffer layer is provided. The wafer structure comprises a wafer which has at least one pad formed thereon, a passivation layer formed on the wafer for partially exposing the at least one pad, a buffer layer formed on the passivation layer and the pad, and an under bump metallurgy (UBM) formed on the buffer layer. The buffer layer comprises a thickness-increased inner buffering member made from aluminum and located between the UBM and the pad to enhance the shock-absorbing ability of the wafer in a drop test to avoid the conductive bump bonded to a substrate coming off or cracking. The invention can also enhance the bonding between the conductive bump and the UBM. The buffer layer may further comprise an outer buffering member made of polyimide, coated on the passivation layer and partially arranged between the UBM and the passivation layer.