This book constitutes the proceedings of the 21st International Conference on Web Information Systems Engineering, WISE 2020, held in Amsterdam, The Netherlands, in October 2020.The 81 full papers presented were carefully reviewed and selected from 190 submissions.

Network Embedding.- Higher-Order Graph Convolutional Embedding for Temporal Networks.- ROLNE: Improving the Quality of Network Embedding With Structural Role Proximity.- Weighted Meta-Path Embedding Learning for Heterogeneous Information Networks.- A Graph Embedding Based Real-time Social Activity Matching Model for EBSNs Recommendation.- Competitor Mining from Web Encyclopedia: A Graph Embedding Approach.- Graph Neural Network.- Fine-grained Semantics-aware Heterogeneous Graph Neural Networks.- DynGCN: A Dynamic Graph Convolutional Network Based on Spatial-Temporal Modeling.- NeuLP: An End-to-end Deep-learning Model for Link Prediction.- PLSGAN: a Power-Law-modified Sequential Generative Adversarial Network for Graph Generation.- Social Network.- User Profile Linkage across Multiple Social Platforms.- Budgeted Influence Maximization with Tags in Social Networks.- Modeling Implicit Communities from Geo-tagged Event Traces using Spatio-Temporal Point Processes.- Detecting Social Spammers in Sina Weibo Using Extreme Deep Factorization Machine.- Clustering Hashtags Using Temporal Patterns.- Nonnegative Residual Matrix Factorization for Community Detection.- Graph Query.- Fast Algorithm for Distance Dynamics-based Community Detection.- A hybrid index for exact shortest distance queries.- DySky: Dynamic Skyline Queries on Uncertain Graphs.- Leveraging Double Simulation to Efficiently Evaluate Hybrid Patterns on Data Graphs.- Knowledge Graph and Entity Linkage.- Knowledge-Infused Pre-Trained Models for KG Completion.- TransMVG: Knowledge Graph Embedding based on Multiple-Valued Gates.- ADKT: Adaptive Deep Knowledge Tracing.- MULCE: Multi-Level Canonicalization with Embeddings of Open Knowledge Bases.- Encoding Knowledge Graph Entity Aliases in Attentive Neural Networks for Wikidata Entity Linking.- Improving Entity Linking with Graph Networks.- Spatial Temporal Data Analysis.- AccurateIndoor Positioning Prediction Using The LSTM and Grey Model.- Bus Travel Time Prediction Based on Deep Spatio-Temporal Model.- TraSP: A General Framework for Online Trajectory Similarity Processing.- Indicators for Measuring Tourist Mobility.- Modeling Local and Global Flow Aggregation for Traffic Flow Forecasting.- NSA-Net: A NetFlow Sequence Attention Network for Virtual Private Network Traffic Detection.- Spatial and Temporal Pricing Approach for Tasks in Spatial Crowdsourcing.- Service Computing and Cloud Computing.- Attention-based High-order Feature Interactions to Enhance the Recommender System for Web-based Knowledge-Sharing Service.- Designing Context-based Services for Resilient Cyber Physical Production Systems.- A Novel Repair-Based Multi-Objective Algorithm for QoS-Constrained Distributed Data-Intensive Web Service Composition.- Heuristics based Mosaic of Social-Sensor Services for Scene Reconstruction.- Fast Build Top-k Lightweight Service-based Systems.- Comparison of Text-based and Feature-based Semantic Similarity Between Android Apps.- Subjective Metrics-based Cloud Market Performance Prediction.- Towards Web-scale and Energy-efficient Hybrid SDNs: Deployment Optimization and Fine-grained Link State Management.