This paper is devoted to the study of electronic and phonon spectra of a kind of generalized Fibonacci quasiperiodic chain (Twins model). Renormalization group results show that the electronic spectrum has a trifurcating selfs milar structure but the middle subbends in every hierarchy are similar to spetral structure of the periodic systems. The analysis is confirmed by numerical results. While the phoson spectrum shows the same spectral structure as that of the Fibonacci chain.