This paper studies online quality measurement in cloud computing environment. The paper analyzes concentration measure evaluation method of the current software quality evaluation system. As is known to all, the existing evaluation technology uses concentrated evaluation before run-time. By testing and analyzing results, the quality is obtained. In this paper, by analyzing the features in cloud computing environment, we consider that service-oriented evaluation should be mainly based on runtime online measurement. The paper puts forward agent-based online measure infrastructure, which is evaluated by distributed assessment in service computing environment A quality model and corresponding online data collection strategy are described. In this approach, the previous quality evaluation, which is concentrated and simulating in a simulated environment, is substituted. Then, a novel measure method of quality data acquisition, which is based on distributed agent technology, is established. ...