Background: Thiazole derivatives are a category of hetero cyclic compounds that large spectrum of biological activities.Aim: This study aim to study the anti cancer effect of thiazole derivatives invitro and invivo.Methods: Synthesis of thiazole derivatives were examined invitro and invivo .Results: Invitro , IC50 of Compound1 on different human lines colon cancer, breast cancer and liver cancer were found 4.7 ug/ml, 4.8 ug/ml and 11 ug /ml respectively. While IC50 value for Compound 2 were found 9.5 ug/ml , 9.6 ug/ml and 18 ug /ml respectively. Invivo , these compounds were safe up to 500 mg/Kg.Although the most effective doses was 15 mg/kg for Compound1 and Compound2. Thiazole derivatives showed a significant reduction in the volume and count of Ehrlich ascites carcinoma and improve hematological parameters ,liver and kidney functions.Conclusion: Thiazole derivatives have apotent antitumor activity .