Using a pseudo-particle technique we simulate large-amplitude isoscalar giant octupole excitations in a finite nuclear system. Dependent on the initial conditions we observe either clear octupole modes or over-damped octupole modes which decay immediately into quadrupole ones. This shows clearly a behavior beyond linear response. We propose that octupole modes might be observed in central collisions of heavy ions.Giant resonances regain much attention presently for the investigation of many particle effects in finite quantum systems. While most of the theoretical treatments of oscillations rely on the linear response method or RPA methods, large amplitude oscillations require methods beyond. Especially the question of the appearance of chaos is recently investigated [1][2][3]. The hypothesis was established that the octupole mode is overdamped due to negative curved surface and consequently additional chaotic damping [4][5][6]. Here we want to discuss at which conditions one might observe octupole modes at least in Vlasov -simulation of giant resonances.We will consider different initial conditions of isoscalar giant resonances using a pseudo-particle simulation of Vlasov kinetic equation [7]. With a local potential U (r) the quasi-classical Vlasov equation readsWe represent the distribution function f (p, r, t) by a sum of pseudo-particle distributionsand use Gaussian pseudo-particlesat r 1 with momentum p 1 [8]. These pseudo-particles follow classical Hamilton equationsWe assume for the interacting nucleons a phenomenological density dependent Skyrme interaction [9] which results into the mean fieldwith a = −356MeV, b = 303MeV and s = 7/6. The compression modulus is K = 200 MeV. The evolution given by (1) is deterministic, fluctuations appear only due to numerical noise [10]. We are using 75 pseudo-particles per nucleon and a pseudo-particle width, σ r = 0.53 fm, is adjusted so that the isovector giant dipole energy is reproduced at a single mass number. The experimental behavior of centroid energy with mass number is than reproduced. We have checked different numbers of test particles. The dependence of observables on the width is discussed in [11]. Numerically the ground state of nucleons is realized by Wood-Saxon shapes of density and Fermi spheres in momentum. The distribution n a (p) = dra i f (p, r) of mass distribution, a i = 1, isospin, a i = τ i , kinetic energy, a i = p 2 i 2m , and kinetic isospin energy, a i =