Dear Sir or Madam,
I am writing this letter in order to invite you to attend the forthcoming graduation ceremony. The ceremony will be held in the Ceremony Hall at 10 a.m. on December 27th,2017. It is advisable for you to dress formal. Please let us know your decision as soon as possible so that we could send you further details concerned. Since you are so popular among us that we sincerely hope you could accept this invitation and give the graduates a wonderful memory of our campus.
If you are available, we request the honor of your presence. It will be highly appreciated if you could give us an earliest favorable reply.
Yours sincerely,
Li Ming