The hot deformation characteristics of pure molybdenum was investigated in the temperature range of $600{sim}1200^{circ}C$ and strain rate range of $0.01{sim}10.0/s$ using a Gleeble test machine. The power dissipation map for hot working was developed on the basis of the Dynamic Materials Model. According to the map, dynamic recrystallization (DRX) occurs in the temperature range of $1000{sim}1100^{circ}C$ and the strain rate range of $0.01{sim}10.0/s$, which are the optimum conditions for hot working of this material. The average grain size after DRX is $5{mu}m$. The material undergoes flow instabilities at temperatures of $900{sim}1200^{circ}C$ and the strain rates of $0.01{sim}10.0/s$, as calculated by the continuum instability criterion.