Background: There are subtle and substantial changes in hematological parameters during pregnancy and the puerperium total blood volume increases by about 1.5 liter   mainly to supply the needs of the new vascular bed(Taylor, 1979). Pregnant places extreme stresses on the hematological system and understanding of the physiological changes that result as obligatory in order to interpret any need for therapeutic intervention. (William and Cindy 2005). Iron deficiency is the most common cause of anemia in pregnancy (Odekule 2010). As consequences various quantitative and qualitative hematological changes occur during pregnancy including cell counts, hemoglobin levels, hematocit, leucocytes, thrombocytes, red blood cells indices, morphological changes and reticulocyte production index. (Lewis et al. 2001). Methods:  This a case control study in which    100 pregnant women were enrolled as study group and 50 non pregnant healthy women as control subjects. The  study  was conducted at Omdurman Al Saudi Maternity Hospital  in period  from 5/3/ 2011 to 6/6/ 2011 to  evaluate hematological parameters of Sudanese pregnant and to establish   classification of anemia's on bases of complete blood count (CBC), reticulocyte  production index (RPI) and  peripheral blood picture. Results: The study revealed that there were significant  decreased in  RBCs count, hemoglobin (Hb) and packed cell volume (PCV) of pregnant women  compared to non pregnant women (P value <0.05) and significant decreased in mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH)  and mean corpuscular hemoglobin concentration (MCHC) of pregnant women (P value <0.05). TWBCs count was increased significantly (P. value < 0.050) in contrast platelets count   significantly lower than the normal control (P. value <0.05). On bases of blood picture we classified anemia's of pregnancy as normocytic normochromic 37 (37%) with RPI mean value of 0.49±0.2, microcytic hypochromic 52(52%) with RPI mean value of 0.76±0.6, and dimorphic picture11 (11%) with RPI of mean value  2.1±0.8. Conclusion: We observed significant decreased in RBC count, hemoglobin, PCV, red cell indices and platelet count during pregnancy and significant increased in leukocyte count of pregnant women when compared to non pregnant women. We found the most common type of anemia among Sudanese pregnant women is microcytic hypochromic type  and  likely to be of iron deficiency  second class is normocytic normochromic type, and  less of occurrence type is dimorphic picture types with increased reticulocyte production index results from prophylaxes iron response.