This book provides a series of gesture and behavior recognition methods based on multimodal datarepresentation. The data modalities include image data and skeleton data, and the modeling methods includetraditional codebook, topological graph, and LSTM architectures. The tasks include single gesture recognitionclassification, single action recognition classification, continuous gesture classification, complex behaviorclassification of human interaction and other tasks of different complexity. This book focuses on the dataprocessing methods of each modality, and the modeling methods for different tasks. We hope the reader canlearn basic gesture and action recognition methods from this book, and develop a model system that suits theirneeds on this basis. This book can be used as a textbook for graduate, postgraduate and PhD students majoring in computerscience, automation, etc. It can also be used as a reference for the reader who is interested in gesturerecognition, human action inter