Thin molybdenum sheet is a promising material for aerospace applications. Quantifying the mechanical behavior of the molybdenum sheet at elevated temperatures is important to understand the formability of the molybdenum component. To this end, tensile tests were carried out at different temperatures (20-500℃) and strain rates(5×10-4-1×10-2s-1). The rheological, normal anisotropic and fracture behaviors during tension were analyzed. The results show that the deformation resistance of thin pure molybdenum sheet is sensitive to temperature while the r-value (Lankford parameter) varies little within the test temperature range. When the temperature is below 300℃, the strain hardening exponent increases with increasing temperature, and it tends to be stable when the temperature is above 300℃. With the increase of temperature, the elongation to fracture of pure molybdenum sheet increases and then decreases slightly. The crack is generated at the grain boundary, and the separation of crystal grains along grain boundaries causes delamination of fractures. A modified Johnson-Cook model was established to characterize the constitutive behavior of the molybdenum sheet, of which the mean error is less than 5%.