Many internet and enterprise applications now not only use XML (eXtensible Markup Language) as a medium for communication but also for storing their data either temporarily for an application or permanently as a means to represent their data. Most of these applications need to follow a set of rules, which are called as integrity constraints in the context of databases. We assume a setting in which data is distributed across multiple sites. In this paper, we introduce a notation for representing constraints affecting multiple XML databases, Global XConstraints. A single update on one site can cause these global XConstraints to be violated. Hence, we propose a framework for checking these constraint violations using Schematron. As a proof of concept, we present a prototype of our system implementation. Most of the processing in our approach happens in compile time; hence we save time during run time. Keywords XML Constraints, Global XML Constraint Checking, Schematron, XSLT, XML Databas...