This paper deals with regulation control on the basis of genealogical decision trees (GDTs). GDTs are a population-based random search technique for solving sequential multimodal and multivariable trajectory tracking problems, when gradient information is not available or does not exist. A direct application of GDT results in an open-loop control. In this paper, feedback regulation based on GDT is considered. In the proposed scheme, GDTs are used for solving off-line a number of predictive control problems; a finite set of initial states is then constructed from these simulations, for each of which an optimal control sequence has been computed. Natural handling of missing state vector measurements is provided. Numerical examples dealing with the van der Vusse CSTR illustrate the feasibility and the efficiency of this feedback control algorithm. A discussion on alternative approaches and a numerical comparison with the Markov-decision-process-based optimal policy are provided.given the observations. Particle filters have a number of attractive characteristics. In particular, they are non-parametric and can represent arbitrary distributions.Particle filters are today commonly used in the area of nonlinear filtering. Recent results allow us to quantify with precision their ability to also solve any optimal control problems that can be interpreted in terms of a nonlinear filtering problem. Lately, GDTs have been introduced for solving open-loop regulation and tracking control problems [11,12].The GDT-based control approach is a random search technique for solving a sequential optimization problem. The algorithm is simple to implement, the number of design parameters is limited and the values of the parameters are easy to choose. The computational load can be heavy, however, and as the approach is model based, the performance depends on the availability of a reliable state-space model. A number of GDT-based process control examples along with clear rules for tuning the algorithm parameters have been reported [13].This paper presents a regulation approach based on an extensive use of a process model. The essential idea is to use GDT optimization for solving off-line a number of predictive control problems. A finite set of initial states is then constructed from these simulations, for each of which an optimal control sequence has been computed; these trajectories are then used for setting up a controller. The idea is new; we are not aware of any similar approaches using particle filtering techniques for solving optimal control problems. Instead, the majority of control applications focus on obtaining better control via improved state estimation using particle filter algorithms to estimate the states of the system online to identify the most probable operating condition.The GDT problem formulation and optimization algorithm are covered in Sections 2-4. The application to regulation is described in Section 5. Numerical examples in Section 6, dealing with van der Vusse continuous stirred-tank reactor (CSTR) and rapid therm...