Software metrics is vital for the management of software development, especially when a new technology is adopted and established practices have yet to be developed. As a kind of software components, web service technology has flourished and attracted a flurry of research activities. Despite the vast amount of research on mechanisms of web services, there have been little investigations of the overall nature of existing web services from a software component point of view. This paper is the first attempt to compare web services with other software components in terms of established metrics in software engineering, including object oriented metrics and interface metrics. In this study we conclude that there are statistical differences between the interface, variable name and other OO metrics when one compares a large sample web services with typical OO systems. The distributions obtained give insight into the typical characteristics of web services and can be used to identify candidates...