传质（英语：Mass transfer）是体系中由于物质浓度不均匀而发生的质量转移过程。

体系中由于熵自动向最大值移动，即趋向均匀，如果各部分温度不均匀，会趋向一个平均温度，如果浓度不均匀，也会趋向一个平均浓度，但浓度的传递必须发生在流体中间，可以是两种流体之间，也可以是一种流体和固体之间传质（如萃取），但不可能在两种固体之间发生传质过程（虽然可以发生传热过程）。

在化学工业中，一般应用的是气-液系统；液-液系统和固-液系统之间的传质过程。

Weight transfer and load transfer are two expressions used somewhat confusingly to describe two distinct effects: the change in load borne by different wheels of even perfectly rigid vehicles during acceleration, and the change in center of mass (CoM) location relative to the wheels because of suspension compliance or cargo shifting or sloshing. In the automobile industry, weight transfer customarily refers to the change in load borne by different wheels during acceleration. This is more properly referred to as load transfer, and that is the expression used in the motorcycle industry, while weight transfer on motorcycles, to a lesser extent on automobiles, and cargo movement on either is due to a change in the CoM location relative to the wheels. This article uses this latter pair of definitions.