Abstract: The feed formulas and feeding standards to meet the nutrient requirements of the Arbor Acres and Redbro chickens raised in Fuzhou area were investigated according to the climatic condition and available feed-resources, especially based on the nutrient compositions of feeds usually used there. By the help of the technology of micro computer and the references of feeding standards for these two breeds, twenty-five formulas of three kinds of energy and protein levels were calculated to be nutritionally adequate during starter (1 to 30 days of age) grower (31 to 49 days of age) and finisher (50 to 56 days of age) phases. All experimental feed ingredients were supplied by the local feed company. Three feeding trials were conducted with 15,000 chickens. After 56 days’ feeding, the results showed that: (1) in the group of high nutrition level, the average body weight and gain-feed ratios of Arbor Acres were 1.98 to 2.23 kg and 1 : 1.99 to 1 : 2.28 respectively and those of Redbro were 1.70 to 1.94 kg and 1:2.06 to 1:2.27 rexpectively; (2) in the group of middle levei, those of Arbor Acres were 1.96 to 2.15 kg and 1 : 2.04 to 1 : 2.23 respectively, and those of Redbro were 1.67 to 1.91 kg and 1 : 2.1.3 to 1 : 2.30 respectively; (3) in the group of low level, those of Arbor Acres were 1.80 to 2.02 kg and 1 : 2.27 to 1 : 2.39 respectively, and those of Redbro were 1.56 to 1.77 kg and 1 : 2.27 to 1 :2.50 respectively.The statistical analysis indicated that the net gain of either Arbor Acres or Redbro was no significant difference (P0.05) between the high and middle level, but the significant difference (p 0.01) between the high and low level was found and the difference between the middle and low level was significant (p0.05) or very significant (p0.01) . Summing up the results of metabolic test, carcass measurement, comparative slaughter assay and L16(43) orthogonal experimental design in the group of middle nutrition level, we suggested that the best formula composition was formula No.9 in starter period, No.8 in grower and No.4 in finisher. It was named the fourth formula of broiler chicken’s mixed feed. Through 2,000, 000 chickens feeded in Fuzhou area, we concluded that the mixed feed produced with the fourth formula had more advantages of well-gainad weight and high feed conversion ratio than other formulas for broilers.