First of all, just making sure you know that to describe a new species one has to follow taxonomic procedure and the rules set by the ICZN (http://iczn.org/) :)) See here: http://www.jstor.org/stable/10.7312/wins06824 (the book is actually freely available @ReserchGate, just search for it ;))
Second, COI gene sequences can be helpful if you have or obtain sequences for a number of closely and distantly related species. It would be a very nice set of additional data for your publication.
Moreover, DNA barcoding is shown to be very handy in modern taxonomy! See here: http://sysbio.oxfordjournals.org/content/54/5/852.extract
Thank you so much, Madam Olga ! I have downloaded d e-book :) and regarding the COI gene sequence, can I use the sequences that available in NCBI or BOLD taxon ? If you don't have any problem then can I have your email id ma'm ? Thanks again..