The simplest analytical theory of bars made of stars in excentric orbits is suggested below (such a possibility was mentioned in [1]). Approximately, the subsystem of particles with elongated orbits may be described as consisting of hard “needles” elongated along radii, slowly (compared with radial oscillations of particles) rotating due to orbit precession. As a first approximation, we shall consider the needles mentioned to be infinitesimally thin ones. Besides, let us assume for simplicity that the radial energy of stars is fixed: E=Eo. Then we may introduce the distribution function of such needles, f=f(ϕ, Ω), so that dn = f(ϕ, Ω)dϕdΩ is the number of needles within the angles (ϕ, (ϕ+dϕ), rotating with the angular velocities Ω = ϕ, in the range (Ω, Ω+dΩ). Let us write now the collisionless kinetic equation in the form ∂f/∂t + Ω. ∂f/∂ϕ+P∂f/∂Ω = 0, where P=dΩ/dt=d2ϕ/dt2=Mtot/I; Mtot is the total torque acting on the needle, I is the needle's inertia momentum relative to the disk center.