A　new　intersection　traffic　signal　control　algorithm　based　on　mobile　control　agent　technology　and　idea　of　＇local　simple,　remote　complex＇　was　proposed.　With　mobile　control　agent　software,　all　kinds　of　traffic　signal　control　algorithms　were　encapsulated　and　transformed　to　correspond　mobile　control　agents　(MCA),　which　could　be　deployed　to　or　recalled　from　traffic　signal　controllers　located　at　urban　intersections　by　network　monitor　center　according　to　real-time　traffic　flow　situation　in　each　intersection.　It　means　traffic　signal　controllers　only　require　less　memory　and　processing　power,　that　is　to　say　＇control　on　demand＇　which　realizes　low-cost　self-adaptive　intelligent　traffic　signal　control.