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The effects of nitrogen (N) on crop yields have historically been assessed with field trials, but selection and use of the best sources and optimal timing N applications have a significant role in realizing the maximum potential of oilseeds quality and quantity. This study was conducted to determine the combine effects of N sources (ammonium nitrate (AN), ammonium sulfate (AS), sulfur coated urea (SCU), and urea (U)) and split N fertilization ((1/4,3/4,0), (1/3,1/3,1/3), (1/2,1/2,0), and (1/3,2/3,0)) on safflower (Carthamus tinctorius L.) some growth characters, yield and seed quality, and N use efficiency based on a split plot design with three replications at the experimental research station, Shiraz University in 2015 and 2016. The highest safflower dry matter (5140.93 kg ha-1), seed yield (3303.52 kg ha-1) and protein yield (694.95 kg ha-1) were achieved with the application of AN fertilizer in a split pattern of 1/2,1/2,0 (applying half of the N at sowing time and the rest at stem elongation), while the highest oil yield (753.09 kg ha-1) was observed by U fertilizer and similar split pattern. Applying AN fertilizer and split patterns of 1/3,2/3,0 (applying one third of the N at sowing and two thirds of the N at stem elongation) and 1/4,3/4,0 (applying one quarter of the N at sowing and three quarters at stem elongation) maximized safflower N uptake efficiency (NUpE) (0.78 kg kg-1). However, the highest N utilization efficiency (NUtE) (43.70 kg kg-1) was obtained when AN fertilizer in a split pattern of 1/2,1/2,0 was applied. On the contrary, applying AS and SCU fertilizers was less effective on safflower performance by all split patterns. It is concluded that applying AN fertilizer in a split pattern of 1/3,2/3,0 and or U fertilizer in a split pattern of 1/2,1/2,0 not only enhanced safflower growth, yield and seed quality improved, but also increased the N use efficiency of safflower.