Abstract: Starting from the basic theory of the composite right-and left-handed (CRLH) transmission line (TL), instate microwave millimeter-wave semiconductor materials and devices, solid-state microwave millimeter-wave circuits this paper, the difference in phase response between the CRLH-TL and the conventional TL is analyzed according to the transmission property, which process reveals that the CRLH-TL can realize quarter-wavelength response at two arbitrary frequencies and zero-degree response at one arbitrary frequency because of the positive non-linear and negative linear phase response of the LH-TL and RH-TL, respectively. Based on the two characteristics, a T-type dual-band transmission line and a multi-band transmission network are designed. Different with the pure CRLH-TL, the T-type dual-band TL and multi-band transmission network featuring high selectivity and high design flexibility in introducing additional passbands, respectively. In the meantime, the two structures are also used in the design of dual-band Wilkinson power divider (PD) and tri-band Gysel PD, which shows CRLH-TL has the excellent characteristics in realizing multi-band, miniaturized, and low loss transmission,giving a strong theoretical and experimental basis for CRLH-TL leading the new change of future miniaturized and low-loss transmission.