To solve two-dimensional boundary-value problems of elasticity, two iteration algorithms of the domain decomposition method are proposed: parallel Neumann-Neumann and sequential Dirichlet-Neumann. They are based on the hybrid boundary-finite-element approximations. The algorithms are proved to converge. The optimal parameters are selected using the minimum-residual and steepest-descent methods. Some plane problems of elasticity are solved as examples, and stationary and nonstationary iteration algorithms in these examples are analyzed for efficiency Keywords: domain decomposition method, finite-element method, direct boundary-element method, parallel Neumann-Neumann algorithm, sequential Dirichlet-Neumann algorithm, plane problems of elasticity Introduction. Domain decomposition methods (DDMs) constitute a class of methods that reduce boundary-value problems of mathematical physics on complex domains to problems on simpler subdomains. The subdomains do not overlap, unlike those in the Schwarz method [3,6]. First DDM algorithms were proposed in [5,7] for Poisson's equation and in [11] for equations of elasticity. Studies on the subject are reviewed in [1,6,22]. An ingenious domain decomposition method was proposed in [8] to solve the heat-conduction problem for a body with a thin coating. A number of some other original numerical analytic approaches to study the mechanical behavior of elastic bodies are outlined in [13][14][15][16][17].In constructing parallel and sequential iteration DDM algorithms for boundary-value problems of elasticity, the initial domain is split into a finite number of nonoverlapping subdomains. Boundary conditions (kinematic, static, or mixed) sufficient to solve problems on the subdomains are set at the interfaces between subdomains. After finding solutions on subdomains, we obtain residuals of interfacial displacements or/and stresses. They are used to establish new boundary conditions for the subdomains. The process is continued until achieving prescribed accuracy. This is how sequential DDM algorithms work, with the order of subdomain traversal being set. Parallel and sequential DDM algorithms can be combined.Iteration DDM algorithms should converge. To this end, it is necessary to justify them and to select stable methods to solve problems on subdomains because determining the stresses on the domain boundary from the set displacements is an ill-conditioned mathematical problem of elasticity.An important advantage of the DDM is the possibility of using different mathematical models and different numerical methods to solve problems on subdomains and the possibility of organizing parallel calculations.