The paper begins with describing the application and technological development of optical fiber communications in backbone transport network of national broadband network

including broadband optical fiber amplifier

dense wavelength division multiplexing

laser modulator integration

opto-electronic integrated receiver

photonic devices and all optical network. Then

it describes the application of optical fiber transmission in local access network

CATV network

and local area network

including three cases of FTTH

FTTC

FTTB

and two methods of hybrid fiber &. coax

and passive optical network. Finally

the paper predicts the future prospect of communication network infrastructure

involving the fixed &?mobile convergence

fiber &?wireless development at same time

and the necessity of continued development of optical fiber communications.