IN THE present study, the effect of temperature (20/10 ºC and 35/20 ºC) on the activities of esterase, peroxidase, protein profile and growth parameters in two different plants (Vicia faba cv. Assuit 95/2 and Zea maize cv. Hi Tech 20*30) was investigated. Vicia faba cv. Assuit 95/2 was grown in pots at optimum temperature 20/10 ºC exposed to heat stress 35/20 ºC. While Zea maize cv. Hi Tech 20*30 was grown in pots at optimum temperature 35/20 ºC exposed to cooling stress 20/10ºC for 15 days. Behavior of esterase, peroxidase, protein profile, growth parameters, and metabolic constituents of Vicia faba and Zea maize plants varied between increase and shortage under heat stress and also between two organs shoot and root. Under high temperature, the growth parameters (fresh weights, dry weights, length and leaf area) were greatly reduced. It can be observed that the two plants responded to the unfavorable conditions (heat stress) by the change in their activities of enzymes, in the number of isoenzymes which include esterase (EST) and peroxidase (PX) and also changes in their biochemical composition actor in the amount of protein, carbohydrates and proline.