Abstract: Heat transfer experiments to obtain heat transfer limit at different temperatures and the effect of gravity on heat transfer limit for heat pipe with arteries were performed. The heat pipe was started up under vacuum condition, and the angle adjustable bench was built to obtain properties of heat transfer limit at different angles. The profiles of the limit heat transfer power for heat pipe were got at the working temperature from 400 ℃ to 650 ℃ and at different angles. Under the temperature of 510 ℃， the limit of heat transfer for this type heat pipe is sound velocity limit. Gravity has little effect on heat transfer limit under the angle zone ±10°. The limit heat transfer power of this type heat pipe is 2.8 kW.