We study the model of two interacting particles moving in a 1D box, paying main attention to the quantum-classical correspondence for the average shape of quantum eigenstates and for the local density of states (LDOS). We show that if the classical motion is chaotic, in a deep semi-classical region of a quantum system, both the shape of eigenstates and of the LDOS coincide with their classical analogs, on average. However, individual eigenstates exhibit quite large fluctuations which may not be treated as statistical ones. Thus, comparison of quantum quantities to the classical ones allows one to detect quantum effects of localization which for conservative systems emerge in the energy space.Recently, a novel approach has been developed for a model of two-body random interactions with a finite number of Fermi particles [1 to 3]. The goal of this approach is to study the relation between the average shape of chaotic eigenstates on the one hand, and the distribution of occupation numbers for single-particle levels, on the other hand. As shown before, there is no need to know exactly the eigenstates of a (chaotic) system since only the shape of eigenfunctions (SEF) in a proper basis comes into play, provided that the unperturbed density of states is also known. The important point is that in some cases, the SEF can be found analytically from the off-diagonal matrix elements of the Hamiltonian matrix. Moreover, if a quantum system has a well-defined classical counterpart, and in the classical limit the total Hamiltonian (of a correspondent dynamical system) is chaotic, then one can use the quantum-classical correspondence for the SEF, thus introducing a new kind of semi-quantum approach. Similar to the SEF, one can define the classical analog of the so-called local density of states (LDOS) which is of great importance in the study of quantum complex systems such as many-electron atoms, heavy nuclei, atomic clusters, and solid-state models [4].In this paper, we extend the above approach to a specific dynamical model of two interacting particles in a one-dimensional box, in a way similar to that used recently in Refs. [5,6] for two interacting spin-particles. The aim of this study is two-fold. First, we demonstrate how the generic approach suggested in Refs. [7,8] can be extended to dynamical models. Second, using the quantum-classical analogy for the SEF and LDOS, we study quantum effects of localization in energy space. We would like to stress that the notion of the quantum localization for conservative systems is quite different from L. Meza-Montes et al.: Two Interacting Particles in a 1D Box