Abstract: By assaying leaf，fruit and soil samples of 100 individual plants in 50 Newhall naval orange（Citrus sinensis）orchards，which were situated in mid-subtropics soil region in northwest Fujian and located at latitudes ranging from N25°3′27″–N27°8′，H 160–660 m，the relationship between concentrations of 26 mineral elements and fruit quality and yield per plant were studied. Results showed： ①The contribution rates of fruit quality indexes，TSS，CF，titrable acid and single fruit weight，to fruit-quality were 36.5%，27.1%，20.0 and 16.1%，respectively；While those of mineral element level in leaf，including K，Cu，Ca，N，Ni，B，Cd，P and Mg，were 15.8%，11.3%，11.2%，10.5%，8.7%，8.7%，7.8%，7.4% and 7.3%，respectively，and amounted to 88.7%. ②According to standard regression analysis，the influence rates of different mineral element levels on yield per plant，from the highest to the lowest，were La（–0.553），Ni（–0.405），Zn（+ 0.395），and Cu（–0.377）. ③ Sixteen mineral elements were recommended for leaf nutrient diagnosis in Newhall navel orange（< lack；minimum–maximum；> over）：N（2.7%–3.2%），P（0.13%–0.20%），K（1.2%–1.9%；> 2.2%），Ca（2.5%–4.0%），Mg（< 0.20%；0.22%–0.45%），Cu（5.0–25 mg · kg^-1；> 60 mg · kg^-1），Zn（20–50 mg · kg^-1），Fe（50–200 mg · kg^-1），Mn（20–150 mg · kg^-1），B（< 20 mg · kg^-1；35–150 mg · kg^-1），Mo（0.05–1.0 mg · kg^-1），S（0.28%–0.40%），Cl（< 0.2%；> 0.5%）；Limited elements Ni（≤ 3.0 mg · kg^-1），Cd （≤ 0.3 mg · kg^-1），La（≤ 12 mg · kg^-1）.

Key words: citrus, Newhall navel orange, leaf, mineral elements, fruit quality, yield per plant, the optimum parameters for mineral nutrition