Abstract: This paper presents a model-based approach to monocular tracking of human body using a non-calibrated camera. The tracking in monocular images is realized using a particle filter and an articulated 3D model with a cylinder-based representation of the body. In modeling the visual appearance of the person we employ appearance-adaptive models. The predominant orientation of the gradient combined with ridge cues provides strong orientation responses in the observation model of the particle filter. The phase that is measured using the Gabor filter contributes towards strong localization of the body limbs. The potential of our approach is demonstrated by tracking of the human body on real videos.