To clarify water consumption characteristics and optimal irrigation strategies for late-sowing winter wheat in seriously water-deficit North China Plain, five spring irrigation treatments, i.e., W0 (no irrigation)，W1 (irrigation at jointing stage), W2 (irrigation at jointing and anthesis), W3 (irrigation at double ridge, booting and anthesis), and W4 (irrigation at double ridge, booting, anthesis and filling stage), were applied in 2005-06 and 2006-07 to investigate the characteristics of water use and yield formation of late-sowing winter wheat under different spring irrigation treatments. The results showed that total water consumption (TWC) increased 230 m3/hm2, and soil water consumption (SWC) decreased 440 m3/hm2 with each additional irrigation (750m3/hm2) under the conditions of late-sowing and no winter irrigation. The water consumption rate was low from sowing to jointing, and restriction of irrigation during this stage reduced TWC significantly. When the first spring irrigation was postponed to jointing stage, the contribution of SWC to TWC was increased to 50%. Only one jointing irrigation before anthesis satisfied basic water requirement of wheat from jointing to anthesis, had no significantly different sink capacity compared with two irrigations (double ridge and booting) before anthesis, and improved ratio of total grain number to total leaf area significantly due to reduced leaf area at anthesis. Under late- and dense-sowing conditions, ear density was the main factor contributing to population sink capacity. With adequate sink capacity, irrigation at grain-filling led to less remobilization of carbohydrates accumulated before anthesis to grains, whereas restriction of irrigation after anthesis could significantly increase remobilization of carbohydrates accumulated before anthesis to grains and their contributions to grain filling. High sink/source ratio enhanced the feedback effect of sink to source, improved dry matter productivity per unit leaf area after anthesis significantly, and compensated for the adverse effect of water stress after anthesis on leaf photosynthesis. The two-year results showed that spring irrigations applied at jointing and anthesis stages could achieve high grain yield and high water use efficiency simultaneously for late- and dense- sowing winter wheat.