Did you try searching for webcam in the search box, and having a look at some of the 309 Questions that ask about webcams ?
You have not indicated whether you want to take still images or movies with your webcam. You have not indicated whether you want to be able to do things like adjust the focus. You have not mentioned your image size or framerate requirements. You have not mentioned whether you have any special requirements about colorspace. You have not mentioned whether it is an IP Cam. You have not mentioned your MATLAB version. You have not mentioned the brand or model of your webcam.
