In the present study four equal groups of male experimental rats were orally treated with two doses of technical alphacypermethrin 96 %( 10.5and5.25 ppm) and two other doses of its 10% EC. formulations (1.2and0.6 ppm) for 28 consecutive days, then blood samples were taken after two weeks from treatment and at the end of experiment. The plasma was separated and assayed for some parameters induct liver, kidney and thyroid functions. The results showed that in case of technical grade, a significant decrease in ALT enzyme activity caused by the high dose ,while significant increases in ALP, AChE enzyme activities occurred by the high and low doses after two weeks from treatment. The two used doses produced significant increase in plasma urea and uric acid cones. by the high dose after two weeks. Triiodothyronin hormone conc. was increased significantly in plasma with the two doses after two weeks then, decreased significantly with the low dose at the end of treatment, while thyroxin hormone conc. was decreased significantly by the low dose after 2 weeks, increased significantly by the two doses at the end of treatment. In case of 10%EC. formulation, significant decrease and increase were occurred in AST enzyme activity with the high dose after 2 weeks and at 28 days, respectively. Significant increase in _ALP enzyme activity was recorded by the two doses after 2 weeks and with the high dose at the end of experiment. AChE enzyme activity was decreased significantly by the low dose at the end of treatment period. Significant increase in plasma urea conc. was occurred by the two doses at the two experimental periods. Plasma creatinine and thyroxin hormone cones. were decreased significantly by the low dose at the end of treatment period.