There are Online tools to detect CpG islands from a sequence (http://www.bioinformatics.org/sms2/cpg_islands.html). However, if you are looking for CpG Islands from the human genome you could analyze existing data. For example, in the UCSC genome browser there is a dedicated track for CpG islands (http://genome-euro.ucsc.edu/cgi-bin/hgTrackUi?g=cpgIslandSuper)

thank u mr. Ulz

by the UCSC database you can see in the browser your targets and numerous tracks including the CpG islands, and get all the associated informations as files by the table browser.

fred

thank u very much mr. fred