Abstract: Generally, most Web applications use relational databases to store and retrieve information. But, the growing acceptance of XML technologies for documents it is logical that security should be integrated with XML solutions. In a web application, an improper user inputs is a main cause for a wide variety of attacks. XML Path or XPath language is used for querying information from the nodes of an XML document. XPath Injection is an attack technique, much like SQL injection, exists when a malicious user can insert arbitrary XPath code into form fields and URL query parameters in order to inject this code directly into the XPath query evaluation engine. Through the crafted input a malicious user would bypass authentication or to access restricted data from the XML data source.Hence, we proposed an approach to detect XPath injection attack in XML databases at runtime. Our approach intercept XPath expression and parse the XQuery expression to find the inputs to be placed in the expression. The identified inputs are used to design an XML file and it would be validated through a schema.