This is the second paper in a series of three papers that are intended to serve as an introduction to the jury system as it currently operates in Australia. The first paper deals with the incidence of jury trials (i.e. when are juries used?) as well as a number of preliminary matters by way of background. This paper deals with the composition of Australian juries (i.e. who is eligible for jury service and how are they selected?). Topics covered here include the number of jurors, the principles of representativeness and impartiality, eligibility for jury service, the preparation or selection of jury rolls, lists, pools and panels, challenges to prospective jurors, jury vetting, and juror remuneration. The third paper contains a discussion of the jury's role (i.e. what do juries do and how do they do it?). Although published separately, the intention was that all three papers be read together.