diff --git a/lphy/src/main/java/lphy/evolution/traits/CharSetBlock.java b/lphy/src/main/java/lphy/evolution/traits/CharSetBlock.java
index 4e2ae5b23..4ccb9b3ee 100644
--- a/lphy/src/main/java/lphy/evolution/traits/CharSetBlock.java
+++ b/lphy/src/main/java/lphy/evolution/traits/CharSetBlock.java
@@ -45,7 +45,8 @@ public String toString() {
 
     public static class Utils {
         // 1 458-659 3-629\3 662-.\3
-        private final static String CHARSET_REGX = "^([0-9]+)$|^([0-9]+)\\-([0-9]+)(\\\\[0-9]+)*$|^([0-9]+)\\-(\\.)(\\\\[0-9]+)*$";
+        private final static String CHARSET_REGX =
+                "^([0-9]+|[0-9]+\\-[0-9]+|[0-9]+\\-[0-9]+\\\\[0-9]+|[0-9]+\\-\\.\\\\[0-9]+)( ([0-9]+|[0-9]+\\-[0-9]+|[0-9]+\\-[0-9]+\\\\[0-9]+|[0-9]+\\-\\.\\\\[0-9]+))*$";
 
         public static boolean isValid(String str) {
             return Pattern.matches(CHARSET_REGX, str);
diff --git a/lphy/src/test/java/lphy/evolution/traits/CharSetBlockTest.java b/lphy/src/test/java/lphy/evolution/traits/CharSetBlockTest.java
new file mode 100644
index 000000000..310105ad4
--- /dev/null
+++ b/lphy/src/test/java/lphy/evolution/traits/CharSetBlockTest.java
@@ -0,0 +1,61 @@
+package lphy.evolution.traits;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * @author Walter Xie
+ */
+class CharSetBlockTest {
+
+
+
+    @Test
+    void testParseCharSet() {
+        String str = "3-629\\3 1-629\\3 2-629\\3";
+        assertTrue(CharSetBlock.Utils.isValid(str));
+
+        List<CharSetBlock> charSetBlocks = CharSetBlock.Utils.getCharSetBlocks(str);
+        assertEquals(charSetBlocks.size(), 3);
+
+        for (CharSetBlock block : charSetBlocks) {
+            System.out.println(block);
+        }
+        assertEquals(charSetBlocks.get(0).toString(), "CharSet{from=3, to=629, every=3}");
+        assertEquals(charSetBlocks.get(1).toString(), "CharSet{from=1, to=629, every=3}");
+        assertEquals(charSetBlocks.get(2).toString(), "CharSet{from=2, to=629, every=3}");
+
+        str = "1 458-659 897-898";
+        assertTrue(CharSetBlock.Utils.isValid(str));
+
+        charSetBlocks = CharSetBlock.Utils.getCharSetBlocks(str);
+        assertEquals(charSetBlocks.size(), 3);
+
+        assertEquals(charSetBlocks.get(0).toString(), "CharSet{from=1, to=1, every=1}");
+        assertEquals(charSetBlocks.get(1).toString(), "CharSet{from=458, to=659, every=1}");
+        assertEquals(charSetBlocks.get(2).toString(), "CharSet{from=897, to=898, every=1}");
+
+        str = "1 458-659 897-898";
+        assertTrue(CharSetBlock.Utils.isValid(str));
+
+        charSetBlocks = CharSetBlock.Utils.getCharSetBlocks(str);
+        assertEquals(charSetBlocks.size(), 3);
+
+        assertEquals(charSetBlocks.get(0).toString(), "CharSet{from=1, to=1, every=1}");
+        assertEquals(charSetBlocks.get(1).toString(), "CharSet{from=458, to=659, every=1}");
+        assertEquals(charSetBlocks.get(2).toString(), "CharSet{from=897, to=898, every=1}");
+
+        str = "4-457\\3 662-.\\3";
+        assertTrue(CharSetBlock.Utils.isValid(str));
+
+        charSetBlocks = CharSetBlock.Utils.getCharSetBlocks(str);
+        assertEquals(charSetBlocks.size(), 2);
+
+        assertEquals(charSetBlocks.get(0).toString(), "CharSet{from=4, to=457, every=3}");
+        assertEquals(charSetBlocks.get(1).toString(), "CharSet{from=662, to=-1, every=3}");
+    }
+}
\ No newline at end of file