diff --git a/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/CorpusReader.java b/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/CorpusReader.java
index 2ee377d942526c5c3433522004871426a4298199..0f67f3d4f0ec773efc7562cfd6d09b071b5ac4f6 100755
--- a/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/CorpusReader.java
+++ b/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/CorpusReader.java
@@ -157,6 +157,7 @@ public class CorpusReader {
         xmlReader = inputFactory.createXMLEventReader(xmlPosReader);
     }
 
+    //TODO Format checking extract to separate file
     public void checkFormat() {
         try {
             if (currentFile.getName().toLowerCase().endsWith(".tgt")) format = INTERNAL_FORMAT;
@@ -166,6 +167,7 @@ public class CorpusReader {
             else if (checkFormatXCES()) format = XCES_FORMAT;
             else if (checkFormatTEI()) format = TEI_FORMAT;
             else if (checkFormatCCL()) format = XCES_FORMAT;
+            else if (checkFormatJson()) format = JSON_FORMAT;
             else format = UNKNOWN_FORMAT;
         } catch (IOException e) {
             e.printStackTrace();
@@ -173,6 +175,11 @@ public class CorpusReader {
         }
     }
 
+    //TODO Implement correct check
+    private boolean checkFormatJson() {
+        return true;
+    }
+
     public boolean checkFormatTXT() throws IOException {
         String line;
         boolean ok = true;
@@ -272,12 +279,20 @@ public class CorpusReader {
             case CONLLU_FORMAT:
                 current = getTokenFromCONLLUFile();
                 break;
+            case JSON_FORMAT:
+                current = getTokenFromJsonFile();
+                break;
             default:
                 current = null;
         }
         return current;
     }
 
+    //TODO Implement token reder
+    private Token getTokenFromJsonFile() {
+        return new Token();
+    }
+
     public Token getTokenFromTGTFile() {
         String line;
 
diff --git a/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/FileFormat.java b/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/FileFormat.java
index 36d70f3babaf263c08b93d934060343f5cf5d177..5e7aca6f7950f64d62f88bc4bd8e291736722124 100644
--- a/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/FileFormat.java
+++ b/modules/termopl-core/src/main/java/pl/ipipan/termopl/core/readers/FileFormat.java
@@ -6,5 +6,6 @@ public enum FileFormat {
     XCES_FORMAT,
     TEI_FORMAT,
     CONLLU_FORMAT,
+    JSON_FORMAT,
     INTERNAL_FORMAT
 }