To evaluate the protein nutritional value fed milk powder containing recombinant human lactoferrin derived from transgenic cloned cattle.Methods Based on gender and weight, 100 weanling SD rats were randomly divided into five groups, casein normal control group, recombinant human lactoferrin milk powder group, normal milk powder control group, recombinant human lactoferrin reference group, cattle lactoferrin reference group. They were fed for 28 d. Bodyweight and food consumption were observed,hematology and clinical biochemistry were measured during the experiment period.The rats were sacrificed at the end point for organ weight measurement and pathological examination. The protein efficiency ration and amino acid score were calculated. Results The protein efficiency ratio of rhLF milk power had no significant statistical discrepancy than other control groups in male rats. The result of the female rats was the same. The data of amino acid score of rhLF milk power and normal control group are slightly different.Conclusion The protein efficiency ratio of rhLF milk power equalaled the other milk powder groups. The protein amino acid score of rhLF milk powder showed PHE and TYR were the first limited amino acid.