Abstract. -An exact approach for the factorization of the relativistic linear singular oscillator is proposed. This model is expressed by the finite-difference Schrödinger-like equation. We have found finite-difference raising and lowering operators, which are with the Hamiltonian operator form the close Lie algebra of the SU (1, 1) group.Introduction. -The singular harmonic oscillator is one of the rare exactly solvable problems in non-relativistic quantum mechanics [1,2]. This model is useful to explain many phenomena, such as description of interacting many-body systems [3], diatomic [4] and polyatomic [5] molecules, spin chains [6], quantum Hall effect [7], fractional statistics and anyons [8]. In spite of many interesting papers devoted to the study of the non-relativistic singular harmonic oscillator model [9], the number of works studying relativistic approachs to singular oscillator exact solution is still rather few [10].Recently, we constructed the exactly solvable relativistic model of the quantum linear singular oscillator [11]. Later, this model was generalized for 3D case in [12]. Our model was formulated in the framework of the finite-difference version of the relativistic quantum mechanics, developed in [13][14][15][16][17]. As we noted in [11], unlike the case of the Coulomb potential, the relativistic generalization of the oscillator or singular oscillator potentials are not uniquely defined. Therefore, one of the main requirements for proposed relativistic models is existence of their dynamical symmetry. In this Letter, we present the simplest way for construction of the close Lie algebra of the SU (1, 1) group for a relativistic model of the linear singular oscillator. In spite of expression of the problem under consideration by the finite-difference equation, it is also exactly factorizable and is in complete analogy with relevant non-relativistic problem. This factorization will allow us to obtain the exact finite-difference expression of the generators of SU (1, 1) group.