Data of material property uncertainty, geometrical uncertainty, calculation model uncertainty for overall stability design and load bearing capacity of short columns for Q235, Q345 coldformed thickwalled square and rectangular steel tubes were collected and on this basis, seismic and nonseismic design reliability analysis was conducted through the firstorder secondmoment method. Finally, the resistance partial factor and seismic adjustment coefficient of bearing capacity under strength and overall stability design for Q235 and Q345 coldformed thickwalled steel members were proposed for the reference in current revising of related design codes.