I have use one sub-report in main report with use of jasper Reports. sub-report is print half of is in one page and other half in next page. but i want to print it is in single page. Please help me.
You can set SplitType to equal Prevent in the detail band properties, but that only prevents a band from splitting from page to page, forcing it to begin on the following page of your report. If the output of your sub-report is naturally longer than the page height you have set, then this will just force the sub-report to begin on the following page. I do not think this would be a desirable outcome since in that case the subreport would still populate two separate pages (actually 3 if you include the resulting blank first page).
All that said one solution would be to check off "Ignore Pagination" in your main reports properties. This will ensure that your entire report is viewed as one single page, but this causes problems when printing or PDF'ing.
You are a bit vague in your question, but its also possible that the detail band height is too high. IReport is "pixel perfect" so if the subreport element begins in the middle of the band then that is where it will start. Also if you have title, page header, or column header bands that are not being used, these will result in unwanted white space.
Hope this helps!