diff --git a/src/main/java/haya4/tools/jpmesh/Jpmesh.java b/src/main/java/haya4/tools/jpmesh/Jpmesh.java
index 4a37435..3f35e8b 100644
--- a/src/main/java/haya4/tools/jpmesh/Jpmesh.java
+++ b/src/main/java/haya4/tools/jpmesh/Jpmesh.java
@@ -8,49 +8,110 @@
 
 	/**
 	 * 地域メッシュコードの位置（南西角）を取得する
-	 * @param str	地域メッシュコード
-	 * @return	地域メッシュコードの南西角位置
+	 * @param str	地域メッシュコード（１～４次コード）
+	 * @return	地域メッシュコードの南西角位置。変換できなかった場合にはNULL。
 	 */
 	public static DirectPosition2D getPosition(String str) {
 		if (str != null) {
-			if (str.length() == 8) {
-				double lat1 = Double.parseDouble(str.substring(0, 2));
-				double lat2 = Double.parseDouble(str.substring(4, 5));
-				double lat3 = Double.parseDouble(str.substring(6, 7));
-				
-				double lon1 = Double.parseDouble(str.substring(2, 4));
-				double lon2 = Double.parseDouble(str.substring(5, 6));
-				double lon3 = Double.parseDouble(str.substring(7, 8));
+        	try {
+        		Long.parseLong(str);
+    			if (str.length() >= 4) {
+    				double lat1 = Double.parseDouble(str.substring(0, 2));
+    				double lon1 = Double.parseDouble(str.substring(2, 4));
+    				double lat = lat1 / 1.5 * 3600;
+    				double lon = (lon1 + 100) * 3600;
 
-				double lat = (((lat1 / 1.5 * 3600) + (lat2 * 300) + (lat3 * 30)) / 3600);
-				double lon = ((((lon1 + 100) * 3600) + (lon2 * 450) + (lon3 * 45)) / 3600);
-				return new DirectPosition2D(lon, lat);
-			}
+        			if (str.length() >= 6) {
+        				double lat2 = Double.parseDouble(str.substring(4, 5));
+        				double lon2 = Double.parseDouble(str.substring(5, 6));
+        				lat = lat + (lat2 * 300);
+        				lon = lon + (lon2 * 450);
+        			}
+    				
+        			if (str.length() >= 8) {
+        				double lat3 = Double.parseDouble(str.substring(6, 7));
+        				double lon3 = Double.parseDouble(str.substring(7, 8));
+        				lat = lat + (lat3 * 30);
+        				lon = lon + (lon3 * 45);
+        			}
+        			
+        			if (str.length() >= 10) {
+        				double lat4 = Double.parseDouble(str.substring(8, 9));
+        				double lon4 = Double.parseDouble(str.substring(9, 10));
+        				lat = lat + (lat4 * 3);
+        				lon = lon + (lon4 * 4.5d);
+        			}
+        			
+    				return new DirectPosition2D((lon / 3600), (lat / 3600));
+    			}
+        	}
+        	catch (NumberFormatException e) {
+        		return null;
+        	}
 		}
 		return null;
 	}
 
 	/**
 	 * 地域メッシュコードの位置（中央）を取得する
-	 * @param str	地域メッシュコード
-	 * @return	地域メッシュコードの中央位置
+	 * @param str	地域メッシュコード（１～４次コード）
+	 * @return	地域メッシュコードの中央位置。変換できなかった場合にはNULL。
 	 */
 	public static DirectPosition2D getCenterPosition(String str) {
 		DirectPosition2D ret = getPosition(str);
 		if (ret != null) {
-			double lat = (ret.getY() + (15.0d / 3600.0d));
-			double lon = (ret.getX() + (22.5d / 3600.0d));
+			double lat = (ret.getY());
+			double lon = (ret.getX());
+			if (str.length() >= 10) {
+				lat = (lat + (7.5d / 3600.0d));
+				lon = (lon + (11.25d / 3600.0d));
+			}
+			else if (str.length() >= 8) {
+				lat = (lat + (15.0d / 3600.0d));
+				lon = (lon + (22.5d / 3600.0d));
+			}
+			else if (str.length() >= 6) {
+				lat = (lat + (30.0d / 3600.0d));
+				lon = (lon + (45.0d / 3600.0d));
+			}
+			else if (str.length() >= 4) {
+				lat = (lat + (60.0d / 3600.0d));
+				lon = (lon + (90.0d / 3600.0d));
+			}
 			return new DirectPosition2D(lon, lat);
 		}
 		return null;
 	}
 	
+	/**
+	 * 地域メッシュコードの矩形領域を取得する
+	 * @param str	地域メッシュコード（３次コード）
+	 * @return	地域メッシュコードの矩形領域。変換できなかった場合にはNULL。
+	 */
 	public static Rectangle2D getRectangle(String str) {
 		DirectPosition2D ret = getPosition(str);
 		if (ret != null) {
-			double lat = (ret.getY());
-			double lon = (ret.getX());
-			return new Rectangle2D.Double(lon, lat, 0.0125d, (30d / 3600d));
+			double lat = ret.getY();
+			double lon = ret.getX();
+			double lat2 = 0;
+			double lon2 = 0;
+			if (str.length() >= 10) {
+				lat2 = 15d / 3600.0d;
+				lon2 = 22.5d / 3600.0d;
+			}
+			else if (str.length() >= 8) {
+				lat2 = 30.0d / 3600.0d;
+				lon2 = 45.0d / 3600.0d;
+			}
+			else if (str.length() >= 6) {
+				lat2 = 60.0d / 3600.0d;
+				lon2 = 90.0d / 3600.0d;
+			}
+			else if (str.length() >= 4) {
+				lat2 = 120.0d / 3600.0d;
+				lon2 = 180.0d / 3600.0d;
+			}
+			return new Rectangle2D.Double(lon, lat, lon2, lat2);
 		}
 		return null;
 	}
diff --git a/src/test/java/haya4/tools/jpmesh/JpmeshTest.java b/src/test/java/haya4/tools/jpmesh/JpmeshTest.java
index d0fc874..4c80f69 100755
--- a/src/test/java/haya4/tools/jpmesh/JpmeshTest.java
+++ b/src/test/java/haya4/tools/jpmesh/JpmeshTest.java
@@ -21,13 +21,28 @@
     	assertNotNull(ret);
     	assertEquals(35.683333d, ret.getY(), 0.000001d);
     	assertEquals(139.7d, ret.getX(), 0.000001d);
+    	
+    	ret = Jpmesh.getPosition("5339452600");
+    	assertNotNull(ret);
+    	assertEquals(35.683333d, ret.getY(), 0.000001d);
+    	assertEquals(139.7d, ret.getX(), 0.000001d);
+    	
+    	ret = Jpmesh.getPosition("533945");
+    	assertNotNull(ret);
+    	assertEquals(35.666666d, ret.getY(), 0.000001d);
+    	assertEquals(139.625000d, ret.getX(), 0.000001d);
+    	
+    	ret = Jpmesh.getPosition("5339");
+    	assertNotNull(ret);
+    	assertEquals(35.333333d, ret.getY(), 0.000001d);
+    	assertEquals(139.000000d, ret.getX(), 0.000001d);
     }
 
     @Test
     public void getCenterTest() {
     	DirectPosition2D center = Jpmesh.getCenterPosition("53394526");
     	assertNotNull(center);
-    	assertEquals(35.6875d, center.getY(), 0.000001d);
+    	assertEquals(35.687500d, center.getY(), 0.000001d);
     	assertEquals(139.70625d, center.getX(), 0.000001d);
     }