本文介绍了Windows API的特点和其在Visual Basic中的实际应用， 通过论述Windows环境下的程序运行原理，阐述了API的执行过程，并通过API在Visual Basic中的实际应用论述了相应的声明方法和调用方法，并结合实例从界面编程、多媒体编程、系统编程等方面进行了讨论，最后论述VB中API应用应注意的问题以及解决的办法。

This text has introduced the characteristic of Windows API and its practical application in Visual Basic, through describing the procedure operation principle under Windows environment, execution course to explain API, expound the fact the corresponding statement method and transfer the method through API practical application of Visual Basic, have combined the embodiment and discussed from respects such as programming of interface, multimedia programming, systematic programming,etc., expound the fact finally API employs the methods of problem and settlement that should be paid attention to in VB.