The present invention relates to a catalyst composition comprising the compound represented by the Fischer projection of formula (I) as an internal electron donor, (I) wherein: R1, R2, R3, R4, R5 and R6 are the same or different and are independently selected from a group consisting of hydrogen, straight, branched and cyclic alkyl and aromatic substituted and unsubstituted hydrocarbyl having 1 to 20 carbon atoms; R7 is selected from a group consisting of straight, branched and cyclic alkyl and aromatic substituted and unsubstituted hydrocarbyl having 1 to 20 carbon atoms; and R8 is selected from a group consisting of aromatic substituted and unsubstituted hydrocarbyl having 6 to 20 carbon atoms; N is nitrogen atom; O is oxygen atom; and C is carbon atom. The present invention also relates to a process for preparing said polymerization catalyst composition and to a polymerization catalyst system comprising said catalyst composition, a cocatalyst and optionally an external electron donor. Furthermore, the present invention relates to a polyolefin obtainable by the process according to the present invention and to the use of the compound of formula (I) as in internal electron donor in catalysts for polymerization of olefins.