Abstract: The proved manufacturing technique of the TRIP steel is employed for steel tube production,and thus,a type of light-wall seamless tube in this steel and with a microstrucuture of ferrite,bainite,retained austenite as well as minor martensite is successfully developed.And its mechanical properties and hyrauformability are investigated via conventional tensile test,pipe-end flaring test,ring tensile test and hydraulic free bulge test.As a result,it is identified that the TRIP steel-made seamless tube as developed exhibits excellent axial and circum-ferential mechanical properties as well as good hydroformability,being worth using in the hydroforming field.