With the advances in information technology, healthcare in all varieties of industry is becoming more digital, more cooperative, more patient-centric, and more data-driven. As the use of XML-based electronic clinical information (EMRs) becomes more well-known, so does the need for powerful discovery on them whenever and anywhere. The growing size of healthcare XML files and the difficulty of answering XML queries put new performance requirements to current information management systems. For the reason of supplying rapid and dependable approach for storing and retrieving of huge XML-based electronic clinical information, this paper presents the XML data indexing and querying in the context of the cluster-based computing environment. It introduces a parallelization model for storing and querying big XML data across distributed parallel worker machines. To expose the effectiveness of our approach, we present a prototype implementation of our proposed approach and we present an effective technique to experiment and evaluate this method. Our results demonstrate that parallel XML querying can improve the performance extensively on distributed computing environment.