First of all select an area of accounting in which you are interested more. It might be auditing, finance, book keeping, cost or any other area. It depends on your schooling and expertise. Never try to jump from your area of proficiency to another area of accounting. For example, you are studying and involved in cost accounting from college, but now you are willing to jump in finance area. This will really harm your productivity and you will certainly get stuck with your research process.
After selecting the area, select a topic that you like most. For example, if you have selected auditing as your subject area, then there are various topics available on auditing such as audit risk, company audit, rules and policies of auditing, internal auditing and many more. Select a topic that you find easy and exceptional.
You should research deeply to find a perfect topic for your accounting dissertation papers. Go through the past journals and dissertation papers written on the subject of accounting. This will help you to get aware with the topics on which your seniors have already written dissertation papers. Also keep in mind that it must be so broad that you can easily research on it and collect enough amounts of data for your accounting dissertation paper.
