In the information age, people are increasingly demanding high quality of software systems. Program analysis is one of the important approaches to guarantee the quality of software, and has been receiving attentions from academia and industry. This article mainly focuses on the research progress in program analysis in the last decade. First, the article introduces the basic program analysis techniques, including abstract interpretation, data flow analysis, summary-based analysis, symbolic execution, dynamic analysis, machine learning-based program analysis, etc. Then, it summarizes program analysis approaches for different types of software systems, including mobile applications, concurrent software, distributed systems, binary code, etc. Finally, the article discusses potential research directions and challenges of program analysis in the future.