Using iReport 5.2: In the master report, click on the subreport, and find Parameters in the Properties box. Click on the ... button to open up the Parameters dialog. Click Add and type in a name for the parameter. You will see a button on the right. Click it and you will see all the parameters, fields, and expressions from the master report. Select the field you want to use. Click OK twice to save all this. In the subreport, create a parameter with the same name as the one you just entered in the master report. Now use it like any other parameter, That's all there is to it.