Recently, the YouTube service has been one of the most popular channels to upload and download many video clips. Even in the mobile networks, the user satisfaction on YouTube service becomes the key performance index to benchmark the system quality among various service providers. However, there are many parameters indicating Quality of Service (QoS) of YouTube service. This causes a lot of efforts on both money and time to improve all parameters. It is the fact that users do not concern any QoS parameters as long as they are satisfied with the services. The indicator of user satisfaction is defined as Quality of Experience (QoE). Hence, it would be better if we can know which QoS parameter has the most correlation with QoE. Then, the service providers can spend less money and time to focus on some but important parameters. This paper originally presents the effect of QoS parameters on QoE in order to find the most influencing parameters by surveying the user satisfaction of YouTube services in 3G and 4G networks. The results indicate that the download throughput and the duration to first play provide the strong relationship with user satisfaction while the buffering duration does not play any influences on user satisfaction.