Abstract: This paper considers some aspects related to the sampling plans for human body measurements. In those plans, estimated values are given in the form of percentiles x_p of various human body measuments. A（relative） precision of \hatx_p is defined; the relation of relative precision and sample size n is considered. In this way, the paper gives the methods of estima-ting x_p and determining n. Finally, the sample size for smaking standards of size designation of clothes is also considered.