Dear Sir/Madam/Professor A.,
I am {first name}, a Vietnamese student. I am writing to apply for a post in your program {name, if any} at XYZ university as a graduate student.
At the moment, I am working as {self post} at {company name}. When I was an undergraduate student at ABC university, my major was {field name}. In {year}, with my graduation thesis on {thesis name/field}, I graduated with excellent score. My GPA was X/Y. Linguistically, my TOEFL score is {900}. Please have a look at my attached {CV/undergraduate grade certificate…} for more details. Should you need more information about my background, please feel free to let me know.
In order to fulfill my desire to study more about {field}, I have tried to find schools offering suitable programs. During my research, I came across your research theme on {professor’s research theme name} and found myself with great interest in it. I would be very grateful if you accept me as your student.
Thank you very much for your time and I look forward to hearing from you soon.
Best regards