diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangMust.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangMust.java
new file mode 100644
index 0000000..92a1da3
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+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangMust.java
@@ -0,0 +1,152 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.yangutils.datamodel;
+
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.ParsableDataType;
+
+/*-
+ * The "must" statement, which is optional, takes as an argument a string that
+ * contains an XPath expression. It is used to formally declare a constraint
+ * on valid data.
+ *
+ * When a datastore is validated, all "must" constraints are conceptually
+ * evaluated once for each data node in the data tree, and for all leafs with
+ * default values in use. If a data node does not exist in the data tree, and
+ * it does not have a default value, its "must" statements are not evaluated.
+ *
+ * All such constraints MUST evaluate to true for the data to be valid.
+ *
+ *  The must's sub-statements
+ *
+ *                +---------------+---------+-------------+------------------+
+ *                | substatement  | section | cardinality |data model mapping|
+ *                +---------------+---------+-------------+------------------+
+ *                | description   | 7.19.3  | 0..1        | -string          |
+ *                | error-app-tag | 7.5.4.2 | 0..1        | -not supported   |
+ *                | error-message | 7.5.4.1 | 0..1        | -not supported   |
+ *                | reference     | 7.19.4  | 0..1        | -string          |
+ *                +---------------+---------+-------------+------------------+
+ */
+
+/**
+ * Maintain information defined in YANG must.
+ */
+public class YangMust implements YangDesc, YangReference, Parsable {
+
+    /**
+     * Constraint info.
+     */
+    private String constratint;
+
+    /**
+     * Description string.
+     */
+    private String description;
+
+    /**
+     * reference string.
+     */
+    private String reference;
+
+    /**
+     * Create a YANG must restriction.
+     */
+    public YangMust() {
+    }
+
+    /**
+     * Get the constraint.
+     *
+     * @return the constraint.
+     */
+    public String getConstratint() {
+        return constratint;
+    }
+
+    /**
+     * Set the constraint.
+     *
+     * @param constratint the constraint to set
+     */
+    public void setConstratint(String constratint) {
+        this.constratint = constratint;
+    }
+
+    /**
+     * Get the description.
+     *
+     * @return the description.
+     */
+    public String getDescription() {
+        return description;
+    }
+
+    /**
+     * Set the description.
+     *
+     * @param description set the description.
+     */
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    /**
+     * Get the textual reference.
+     *
+     * @return the reference.
+     */
+    public String getReference() {
+        return reference;
+    }
+
+    /**
+     * Set the textual reference.
+     *
+     * @param reference the reference to set.
+     */
+    public void setReference(String reference) {
+        this.reference = reference;
+    }
+
+    /**
+     * Returns the type of the parsed data.
+     *
+     * @return returns MUST_DATA
+     */
+    public ParsableDataType getParsableDataType() {
+        return ParsableDataType.MUST_DATA;
+    }
+
+    /**
+     * Validate the data on entering the corresponding parse tree node.
+     *
+     * @throws DataModelException a violation of data model rules.
+     */
+    public void validateDataOnEntry() throws DataModelException {
+        // TODO auto-generated method stub, to be implemented by parser
+    }
+
+    /**
+     * Validate the data on exiting the corresponding parse tree node.
+     *
+     * @throws DataModelException a violation of data model rules.
+     */
+    public void validateDataOnExit() throws DataModelException {
+        // TODO auto-generated method stub, to be implemented by parser
+    }
+}