In situ X-ray diffraction patterns of the powder hematite polymorphs were recorded in a temperature range from room temperature (RT) to 1 000℃ in static air and vacuum. Lattice parameters for hematite (RT~1 000℃) in static air and vacuum were refined. The variations of lattice parameters of hematite with temperature were therefore well described. Linear (α) and volume (β) thermal expansion coefficients of hematite (RT~1 000℃) were calculated. The change laws of α and β with temperature for hematite in static air and vacuum were summarized. It is shown that linear (α) and volume (β) thermal expansion coefficients of hematite (RT~1 000℃) are constant with increasing temperature. The thermal expansion coefficients for hematite are α_a=9.603 16×10^-6/℃, α_c=6.647 67×10^-6/℃, β=2.606 33/℃ in static air and α_a=9.006 79×10^-6/℃, α_c=6.891 23×10^-6/℃, and β=2.511 51/℃ in vacuum.