国际单位制基本单位是一系列由物理学家订定的基本标准单位。国际单位制共有七个基本单位。其中，只有公斤是用实物来定义。

中华人民共和国用的单位名称依据《中华人民共和国法定计量单位》。****用的单位名称依据****公告的《法定度量衡单位及其使用之倍数、分数之名称、定义及代号》。

1. 所含基本微粒个数与0.012公斤碳-12中所含原子个数相等的一系统物质的量定义为1莫耳
2. 使用摩尔时，应指明基本微粒，可以是分子、原子、离子、电子或其他基本微粒，也可以是基本微粒的特定组合体。

The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units are derived. The SI base units and their physical quantities are:

The SI base quantities form a set of mutually independent dimensions as required by dimensional analysis commonly employed in science and technology. However, in a given realization in these units they may well be interdependent, i.e. defined in terms of each other.