What is provided is an EPO mimetic peptide derivatives defined as formula (I) and its pharmaceutical salt, the preparation thereof, wherein R 1 , R 2 , R 3 , R 4 , R 5 , n 1 , n 2 are defined as described in description. A composition comprising of an EPO mimetic peptide derivatives defined as formula (I) and its pharmaceutical salt. The uses of the derivatives and its pharmaceutical salt, as well as the uses of the composition described above in treatment of diseases characterized by a deficiency of EPO or a low or defective red blood cell population. €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒR 1 -R 2 -(CH 2 ) n1 -R 3 -(CH 2 ) n2 -R 4 -R 5 €ƒ€ƒ€ƒ€ƒ€ƒ (I)