@gopi seelam The "WordCount" program is written with java "package" instruction ? If yes then you should pass the fully qualified classname. - In order to verify it can you please share the output of the following command this will help us in knowing if you are passing the correct classname there? jar -tvf WordCount.JAR . Also please check if your Jar file name is in Uppercase or lowercase? Like "WordCount.JAR" Or "WordCount.jar" If the jar file name is in lowercase then you should pass the correct file name in same case. $ hadoop jar WordCount.jar WordCount siva/file1.txt . ... View more