What type/kind of clematis do I have? Identification tips
You may have lost the identification tag which came with your clematis, you may have moved into a house with existing unlabelled clematis in the garden, or you may have just found out that your clematis cannot be what it was labelled as when you bought it. This last problem seems to be alarmingly common with clematis. However, if you have purchased your clematis from a respectable nursery, they should be happy to identify your mis-labelled plant and/or replace it with the correct plant. Certain types of clematis can be almost impossible to positively identify. That said, if you still want to try, make a note of the flower color(s), the stamen color, the leaf shape, the overall habit and size of the plant, and when it blooms.
You can then try to place your clematis into the right 'group' which will help narrow down your search. See the FAQ entitled 'Clematis Types and Groups'.
Then, see the FAQ entitled "Where can I find out more information? Clematis Books, Societies, and other resources" for a list of books and other resources that will aid you in your search.
If all else fails, try and post of photo of your flower on the 'Gallery' of the Clematis Forum here. You never know, someone may be able to tell you what they think it is.