A　vector　algorithm　of　sun　tracking　tilt-angle　of　linear　fresnel　reflector　(LFR)　was　presented.　Current　algorithms　of　solar　position　just　can　obtain　azimuth　and　altitude　which　could　not　be　utilized　directly　by　LFR　tracking.　Farther　complex　derivation　must　be　done　for　obtaining　relevant　tracking　tilt-angle　by　which　every　mirror　element　of　LFR　is　controlled　rotating　to　corresponding　position.　The　derivation　of　tracking　tilt-angle　was　simplified　by　appropriately　decomposing　the　sun　vector.