Identify the doctoral degree you are seeking. The doctoral program in business administration is not a "PhD program." Harvard's Business School grants DBA (Doctor of Business Administration) degrees. If you want to pursue a doctoral degree in Business Administration at Harvard, you're going to have to prepare well, and be ready to study long and hard.
Select your field of study. Harvard offers doctoral Business Administration degrees in the major categories of modern business management and management philosophy. These broad categories will be further refined to your particular area of interest when you are accepted into the program and you work with a faculty adviser.
Confirm that you can afford the program. Harvard provides every DBA candidate with a fellowship that includes a $35,400 living stipend (as of 2009), tuition, and health insurance for one person. The expectation is that a comparable fellowship will be awarded to you for up to four years, depending on your ability to satisfy progress goals toward the degree.
Assemble your paperwork. The required application materials include an online application form, your resume, a statement of purpose (why you want the degree), full academic transcripts, your current GMAT or GRE scores (within the last five years), TOEFL scores (if you are not a native English speaker), and three letters of reference, one of which has to come from an academic. If you fail to properly submit the application materials, your application will be rejected right away.