大多數學校都要求申請人提供二至三封推薦信。有力的推薦是錄取的重要條件之一。推薦信要客觀、公正、切忌流於形式，內容空洞，要與申請人的其它材料(如成績單)等相符。推薦信也應注意格式、文法等。因為向來有"名師出高徒"之說。推薦信的格式與一般書信基本相同。有信頭，發信日期，收信人姓名，稱呼，正文，信尾謙稱，簽名，推薦人姓名，職稱及工作單位等部分。但推薦信還應著重以下方面：
1. 為了便於校方查閱，必須提到被推薦者的全名。
2. 必須交待與被推薦者的認識期間(何時開始認識或認識多久)，認識程度(偶爾見面或密切接觸)及關係(師生關係，上下級關係，同事等)。
3. 對被推薦者的優點介紹及評價，這是推薦信的核心。主要包括被推薦者的天賦，學習成績，研究能力，工作經驗，學習精神，組織能力，品行及個性方面。
4. 必須表明推薦人的態度，是極力推薦還是有保留地推薦。
最近一些學校出於各種原因，設計了推薦表格，由推薦人填寫，但其主要內容也和推薦信涉及的相同。
範例1 計算機教授推薦信
at the request of mr. xizhen chen, my former student in the department of computer science, beijing univ. of sciences, i am glad to write this letter furnishing my evaluation of his academic aptitude for your reference. mr. chen is interested in your graduate program in computer science.
i came to know him in september 1987 when mr. chen enrolled in my class on fortran iv programming, a three semesters course.in the class he was one of the most outstanding students. at the semester final he earned a high grade of 81, which should be "a" according to our grading system. i also found him good at other studies.
after the class, he had personal talks with me several times. he indicated a great interest in computer hardware, in my opinion, mr. chen has a potential in computer science, which can be further developed.
in view of his previous achievements in this college, i am firmly convinced that mr. chen will make a successful graduate student.your favorable consideration of his admission will be highly
appreciated.