The current search experiments designed to study the effect of chronic and acute heat stress on the relationship between HSP70, leptin and luteinizing hormones level in female rats. 45 female pups were used in the age of weaning, were randomly divided into three equal groups. 1st
group was a control group, 2nd
group exposed to chronic heat stress at 38 ºC for 1hour a day since the age of weaning until onset of puberty and the 3rd
group exposed to acute heat stress at 38 ºC for 4 hours per day for 5 consecutive days from 35 day age of rat and each group above were secondary divided into 3 age groups consisted of pre-puberty, at puberty and post-puberty. Results of study showed female rats exposed to chronic and acute stress led to significant increase in the level of luteinizing hormone at onset of the puberty. The result showed correlation coefficient between the level of HSP70 and leptin hormone significantly in the females acute stressed group at onset of puberty, as well as female exposed to chronic heat stress led to significant correlation coefficient between HSP70 and leptin hormone at post puberty. The result revealed significant correlation coefficient between HSP70 and luteinizing hormone in female control group at onset of puberty. It concluded from this study there is relationship between HSP70 and leptin hormone at onset puberty during acute heat stress and same relationship at post puberty during chronic heat stress.