This study aimed to identify the species of blood stain whether human or animal by using sodium dodecyl sulphate (SDS)- polyacrylamide gel electrophoresis (PAGE) through determination of bands, rate of flow (RF) and the molecular weight (MW) of proteins. A total of 22 samples of blood stain were collected from human and animal blood. Three human blood stains were derived from the cephalic veins of child (3 years), middle aged male (35 years) and old aged female (62 years) volunteers. The forth human sample was obtained from menstrual blood of young female aged 28 years. Animal blood stains were derived from three different group. The first group was farm animals including cow, camel, horse, dog, cat, sheep, goat, donkey. The 2nd group was experimental animals including rabbit, rat, mice, and guinea pig. The last group include chicken, pigeon, turkey, duck and goose. It was found that the three human samples and rabbit give the same number of bands (14 bands) with similar rate of flow and similar molecular weight. While the number of bands in menstrual blood stain were 22 bands. However the number of bands were variable in the animals samples ranging from 8 (in pigeon) to 26 (in Goat). According to the molecular weight from 31 to 40 kilo Dalton were present in all samples except in middle aged male while MWS from 274- 280 Kda were only present in turkey. Also the RF values were variable in different samples ranges from 0.001 as the first band observed in turkey up to RF 0.925 shown by the last band in chicken on the other hand some bands had identical RF values as in menstrual blood and dog (RF 0.280). In conclusion by using 10% SDS- PAGE, the species of blood stain could be identified the number of bands, RF value and the molecular weight of proteins.