The developmental trend of EHV transmission tower is high strength tube tower. However, present research has been mainly focused on angle tower and domestic design codes do not contain design parameters of steel whose strength is higher than Q420. For this issue, pin-ended experiment of 20 different axially loaded high strength steel tubes was conducted, and the stability analysis of the tubes was done by means of FEA and related codes. The experiment and analysisshowed that Q420, GR65 and Q460 steel tubes have higher strength than corresponding values in domestic codes, and the trend becomes more and more obviousalong with the increase of steel yield strength. The propositional strength reduction formula covered the lower limit of FEA calculation and experimental values, and could be used as a reference for the corresponding designs.
