This p:ipc'r st iidies thc adaptiw traffic congv5tion con trol of tr&c nr.twork from tlic systc,ni-thcorctic vicwpoint. 'Tho tirne-d'p('ri(l('Iit charactc,ristics of traffic conqcstion kngtli are d c s (~i h~d by a linear tinic,-vatyiiig discretv dynaniical system based on thc traffic voliirne l>alaIiw at c~~h signali& intersc~tio~i. We p~o p o w tlic aclapti\e control systeni of the traffic congestion ltqgtli i n a traffic IidwoI k usiiig a dcceiitralixed ccnitiol c o~icept. WP also proposv two adaptive control algorithriis for traffic c-oiigclstioii lvngtli control in a tIaffic 1ic.twork; OIIC is a "pIioIit> roiitrol algoritlirri". the otlivi is a "1)alaiice control idgoritlinl" . Tlie sinmlatioii of two atlirptivr. control dgorithins confirms that thc c y cle h g t l i s . green tiriic arid offs(,ts arc adaptivc~ly controlled nc-cording t o t tie vaIiation of incoming tra& voliinies. m d thr priority and balance control algorithms work wcdl to control tlic traffic congestion lengths itt t WO-adj a ccnt signaliz cd int ('1 w c t ions.