diff --git a/schainpy/model/io/jroIO_base.py b/schainpy/model/io/jroIO_base.py
index 9368c9c..9afb2fc 100644
--- a/schainpy/model/io/jroIO_base.py
+++ b/schainpy/model/io/jroIO_base.py
@@ -1303,7 +1303,7 @@ class JRODataWriter(JRODataIO):
         
         self.basicHeaderObj.size = self.basicHeaderSize #bytes
         self.basicHeaderObj.version = self.versionFile
-        self.basicHeaderObj.dataBlock = self.nTotalBlocks
+        self.basicHeaderObj.dataBlock = self.blockIndex
         
         utc = numpy.floor(self.dataOut.utctime)
         milisecond  = (self.dataOut.utctime - utc)* 1000.0