With the rapid depletion of conventional oil resource, economical and efficient exploitation of heavy oil reservoirs is one of the most effective ways to meet future energy demand. This paper establishes an efficient parametric optimization method for cyclic steam stimulation (CSS) by horizontal wells in heavy oil reservoirs. The net present value (NPV) of a CSS project is maximized by optimizing operational parameters using a new hybrid optimization technique. This hybrid technique is developed by integrating uniform design (UD) into the initialization process of conventional particle swarm optimization (PSO). Case study reveals that initializing PSO with UD can improve the quality of initial particles in conventional PSO and thus speed up its convergence rate. Simulation results indicate that parametric optimization using the hybrid technique is able to obtain the best CSS development strategy for heavy oil reservoirs on both technical and economic sides. (C) 2015 Elsevier Ltd. All rights reserved.