In order to elucidate the interrelationship between electrolytes and exercise the investigation was undertaken to determine the electrolyte levels in young males took on varied environmental temperatures ($13^{\circ}C$, $24^{\circ}C$ or $34^{\circ}C$). 10 healthy young males were used for the experiments. Our results showed the following significant changes; 1. The raising of the environmental temperature, the weight reduction were increased due to marked sweating. 2. In the electrolytes of serum, decreased the $K^+$ concentration at $13^{\circ}C$, but increased the $Na^+$ or $Cl^-$ concentration at $24^{\circ}C$, and increased the $Na^+$ or $Cl^-$, or $Mg^{+}^{+}$ concentrations at $34^{\circ}C$. 3. The raising of environmental temperature appear to be increased PRA,Ang I, Ang II and ALD levels, whereas no changed ADH level. 4. Serum levels of PRA, Ang I, Ang II and ALD were incresed after exercise, and their increments were incresed paralel ttie incresed environmental temperature. However, there no significant change in ADH, level. In conclusion, exercise induced not only changes of serum electrolytes levels such as $Na^+$, $Cl^-$, $K^+$, $Mg^{+}^{+}$, but also serum hormonal changes such as PRA, Ang I, Ang II, ALD. However, ADH level was not changed significantly, These changes were more prominent in exercise at hot temperature than in lower temperature.