Web service selection is a key component in service oriented computing. Due to the vigorous proliferation of web services, numerous web services are available in the internet to satisfy a client request. Furthermore, competition exists among web services readily available to fulfill the request. Selecting a pertinent web service with QoS features is an important issue in web service selection. Selecting the most suitable web sen/ice to a client requirement is paramount important for web service composition. As the candidate web sen/ices are independently required for web service composition, Web service selection becomes imperative. In essence, UDDI may circumvent the QoS based web sen/ice selection. Furthermore, identifying the essential key QoS parameter is still a challenge. Besides, lack of guidance over identifying the major QoS attributes and seldom important attributes that are required for selection process. Besides, no well defined standard for metric and measurement of QoS attribute is another deficit in web service selection. The aforementioned issues must be addressed for efficient web service selection. Many research works have been done in QoS based web service selection. This paper discusses about the emerging challenges and issues incorporate in web service selection and analyze the major parameter which has been used in various research work is compared to the recurrent problem.

Key words:QoS attributes; web service selection; Normalization