The most common cause of excessive burping is related to foods, such as carbonated beverages, beans, and the like. It is also common in people who are lactose intolerant but who are ingesting more dairy products than they can comfortably tolerate. However, if there has been no recent change in your diet then this is unlikely to be the cause in your case.
Another possibility would be dyspepsia, or indigestion. This would be especially likely if you are also having heartburn or another sensation of discomfort under the sternum where the stomach sits. Irritation of the stomach from spicy foods, smoking, alcohol, or infection with a bacteria called Helicobacter pylori may all cause symptoms of indigestion, which might include excessive burping. Burping is rarely a sign of a serious medical problem.
If the symptoms do not resolve and if they are bothersome to you, then your primary care doctor can help you figure out what to do.
Kindly,
Kitt