Two different herbicides isoproturon and metribuzin were stored at zero °C for 7 days and under acceleratedstorage temperature at 54°C for 14 days to study degradation of active ingredient which determined by HPLC-DAD.Physical properties such as change of pH values, suspensibility, wet sieve test, pourability, spontaneity of dispersion andpersistent foam test before and after storage were also studied according to FAO specification. Results showed thatactive ingredient of isoproturon formulation was slightly affected by accelerated storage temperature at 54°C andbecome conformity with FAO specification but metribuzin formulation was affected when stored after 10 days at 54°Cwhile the degradation increasing by long time of storage. Physical properties of two herbicides formulations passedsuccessfully through all storage periods at zero °C for 7 and at 54°C for 14 days except wet sieve test of metribuzin. Onthe other hand, the present two herbicides were evaluated using 1/20 of their LD50 on some biochemical components ofalbino rats in initial time at 23±2°C and after 14 days from storage at 54°C. The results showed that the two herbicidesin initial time caused high decreasing in content of total soluble protein with high increasing in levels of glucose, urea,creatinine, bilirubin, cholesterol and triglycerides. Also the activities of Aspartate aminotransferase (AST), AlanineAminotransferase (ALT) and Alkaline phosphatase (ALP) were high relative to control. In case of two herbicides afterstorage 14 days at 54°C, the results showed slight decrease in content of total soluble protein, but the levels of serumglucose, urea, creatinine, bilirubin, cholesterol and triglycerides were low increase relative to health normal control. Theresults showed that activities of AST, ALT and ALP were the stimulated under the effect of the both herbicidescompared with the normal. The biochemical harmful of the herbicides under storage at 54°C for 14 days was lower thanthose of effect initial time at 23±2°C were compare, the influences of metribuzin on the biochemical study it was morethan that of isoproturon either in initial time at 23±2°C and after 14 days from storage at 54°C.