The vapor pressures and p ρ T properties for trans -1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) are measured using a metal-bellows cell. As for the vapor pressure, eight data points are obtained in the temperature range from (310 to 380) K and pressure range from (703 to 3458) kPa. The data of the vapor pressure is correlated by the Wagner type equation with the absolute average deviation of 0.02 %. By extrapolating the vapor-pressure correlation to the critical temperature, the critical pressure is determined to be 3632 kPa. The acentric factor is also determined to be 0.296 by using the vapor-pressure correlation. As for the p ρ T properties, 26 data points are obtained in the temperature range from (310 to 370) K and pressure range from (2000 to 5000) kPa. The data of the p ρ T properties are correlated by the Sato equation with the absolute average deviation of 0.04 %. Seven data points of the saturated liquid density are obtained by extrapolating the correlation of the p ρ T properties to the vapor pressure.