Abstract: Geometrical configuration of a loop-like structure in solar atmosphere is usually determined by physical features in it.According to conservation of mass,the equation of state in a loop tube, and conservations of momentum along normal direction and inclination direction of a loop tube respectively, a loop-like flux tube of the tornado prominence on August 29,1990 is calculated and the velocity.density and the'magnetic field strength distributions along the loop-like flux tube of the tornado prominence are given in this paper. Results obtained show that the downward motion of the matter within the flux tube is mainly determined by gravity,meanwhile,the density and magnetic field strength distributions are closely related to the geometrical configuration of the flux tube.