Nowadays, Gait is a crucial field for many Pattern Recognition researchers. It is considered as a good way for biometric authentication in many surveillance systems. The most important issue in gait recognition is the features extraction from the silhouettes which are converted from walkers' images or videos. In this paper a new method has been introduced to identify night walker images, which are captured by infrared cameras. The new method depends on the silhouette's presence percentage on different horizontal levels. Minimum distance classifier has been used to choose the active horizontal levels that lead to the highest identification rate. A proposed algorithm which is used to select the Active Horizontal Levels (AHLs) has been presented. The proposed method was evaluated against CASIA silhouette database, to recognize walker into one, or multi silhouettes. The experimental results reveal the effectiveness of our new method against other Gait recognition methods to achieve a better recognition rate.Gait has played an important role in biometric authentication due to its unique characteristics compared with other biometrics. Gait can be captured at a distance and without requiring the prior consent of the observed subject. Most other biometrics such as fingerprints [1], face [2], hand geometry [3], iris [4], voice [5], and signature [6] can be captured only by physical contact or at a close distance from the recording probe. Gait also has the advantage of being difficult to hide, steal, or fake. The techniques used for gait recognition can be divided into two categories: model-based methods and motion-based methods. Model-based methods aim to explicitly model human body or motion, and they usually perform model matching in each frame of a walking sequence so that the parameters such as trajectories are measured on the model. Tao et al. [7] introduced a set of Gabor-based human-gait appearance models and propose a general tensor discriminant analysis (GTDA) to solve the carrying status in gait recognition. Rong Zhang et al. [8] proposed a 2-step, model-based approach, in which reliable gait features we re extracted by fitting a five-link biped human locomotion model for each image to avoid shape information. Sundaresan et al. [9] proposed a hidden-Markov models-based framework for individual recognition by gait. Tan et al. [10] used Orthogonal diagonal projection for gait recognition. Tan et al.[11] recognized night walkers based on one pseudo shape representation of Gait. The effectiveness of model-based methods, especially in body structure/motion modeling and parameter recovery from a walking video, is still limited allowing for current imperfect vision techniques (e.g., tracking and localizing human body accurately in 2D or 3D space has been a long-term challenging and unsolved problem). Further, the computational cost of model-based methods is relatively high. However, motion-based approaches can be further divided into two main classes. The first class called the state space methods. These methods consid...