I'm using SharePoint 2007, custom list.
I have created 2 content type on that list. on the home page I create 2 web part. I want that each content type appear in one web part.
is it possible?
If I understand your question, it can be done this way.
Create two views on the custom list, one for each content type (lets call them ContentA and Content B). In the Filter section of the view, select the "show items only when the following is true" radio button. Set the dropdown for Content Type, 'is equal to' and enter the name of your content type into the text box. Save the view. Repeat this for content type ContentB.
On the home page, add one webpart that shows the first content type by setting the view in the properties of the webpart. Do the same for the other webpart so that it points to the other view.
If you need to query outside of the site or site collection that the list exists in (which you might, gathered the comment on Rich answer), you also have the option of using a Fixed Keyword Query in a Search Core Results web part.
You can use managed properties for your keyword query, eg ContentType:"My ContentType"
Paul Galvin have an example of just that here.