Does your report / subreport run when previewing it in ireport? If not the sub report needs to have parameters and these parameters need to map to fields or parameters on the main report. (In the main report click on the sub report and in properties scroll to the bottom and add Parameter (Name = name of param from subreport, expression = field or parameter in main report). Then you need to change the path of your Subreport Expression to "repo:thenameofyourrepor". Save, compile main report, load onto server in report unit. Then you need to compile your subreport and Add jrxml file / upload them (the easiest way for me) to the Resources folder INSIDE your Report Unit folder. Now the subreport will NOT run in ireport but should work in Run Report Unit (server) This was very confusing for me, 5 hrs. to get it to work. good luck! http://osdir.com/ml/java.jasperreports.general/2006-06/msg00055.html