The present study aimed to shed light on the pathomechanism of chicken infectious anemia disease in chickens experimentally vaccinated with live chicken anemia virus (CAV) -26P4 and -cux-1 strains through investigation of pathogenicity, hematological, blood coagulation and blood biochemical serum parameters. At the75th day of age, 168 chickens were divided randomly into 7 groups, each group contain 24 chickens. Group 1 was subjected to CAV-26P4 vaccinal strain at 75 day of age. Group 2 was subjected to CAV-cux-1 vaccinal strain at 75 day of age. Group 3 was subjected to CAV-26P4 vaccinal strain at 75 & 95 day of age. Group 4 was subjected to CAV-cux-1 vaccinal strain at 75 & 95 day of age. Group 5 was subjected to CAV-26P4 vaccinal strain at 75 day of age and CAV-cux-1 vaccinal strain at 95 day of age. Group 6 was subjected to CAV-cux-1 vaccinal strain at 75 day of age and CAV-26P4 vaccinal strain at 95 day of age. Group 7 was not vaccinated (control). The present study revealed that live CAV-26P4 vaccinal strain inoculated by intramuscular (i.m.) route developed clinical signs and PM lesions, while live CAV-cux-1 vaccinal strain inoculated by oral route did not develop clinical signs but could develop mild PM lesions. Chicken anemia virus-26P4 and cux-1 vaccinal strains cause a significant increase of enzyme linked immunosorbent assay (ELISA) titers mostly at the 5th & 6th weeks post vaccination (PV). A significant anemia, leucopenia, heterophilia, lymphopenia, monocytopenia and thrombocytopenia were observed. All these changes were observed early in birds inoculated with CAV-26P4 vaccinal strain, but were observed later in birds inoculated with CAV-cux-1 vaccinal strain. Both CAV vaccinal strains caused a significant increase of coagulation parameters, liver enzymes and A/G ratio, in addition to a significant hypoproteinemia, hypoglobuliemia. The observed biochemical changes may indicate liver affection.