This paper proposes a 3D motion recovery method from monocular images by statistical inference. The fundamental idea of the paper originates from the mimesis model, inspired by the mirror neuron system. The mimesis model is extended to include motion understanding from monocular image sequences and to imitate whole-body motion patterns in 3D space. In order to achieve this goal, (1) conversion of 3D motion database, represented in probabilistic form, into various spaces is adopted. (2) A vector field approach is developed for natural motion understanding. (3) With the particle filter, a demonstrator’s pose is estimated.