凯氏带（英语：Casparian strip）是高等植物内皮层细胞径向壁和横向壁的木栓化和木质化的带状增厚部分，主要功能是阻止水份向组织渗透，控制着皮层和维管束之间的物质运输。其宽度随不同种植物而有较大的差异。

最初由德国植物学家罗伯·凯斯伯里 (Robert Caspary,1818年–1887年) 于1865年发现其为细胞壁的构造，即以他命名。

凯氏带见于初生根的内皮层，而在茎、叶等气生器官中是否存在则仍有争议。卡氏带在植物根部水与无机养分的运输中，主要影响质体外运输途径，亦即水与无机养分经由表皮、外皮层及皮层细胞之细胞壁间质传递运输。水与无机养分来到内皮层细胞时，因凯氏带之不透水性质而转由内皮细胞之细胞膜间质传递，最终进入中柱内的木质部细胞。

In plant anatomy, the Casparian strip is a band of cell wall material deposited in the radial and transverse walls of the endodermis, and is chemically different from the rest of the cell wall - the cell wall being made of lignin and without suberin - whereas the Casparian strip is made of suberin and sometimes lignin. The Casparian strip might be viewed rather like mortar in a wall that blocks the passive flow of materials such as water and solutes. Water and solutes are pumped into the stele through special endodermal cells called passage cells. The Casparian strip prevents those from leaking back out to the cortex. The band was first recognized as a wall structure by Robert Caspary (1818–1887).