as是英语合同中最常见的虚词之一，通常与其他词组成具有特殊意义的词组：

1.as from/of 自某日起；

例：This Contract shall be in effect for one year as from the 26th March 2013.（本合同自2013年3月26日起生效，有效期为一年）

2.as放在代表“规定”的provide，stipulate等的过去分词前，为“依照...规定；

例：Based on their respective Venture interests as set forth in Section 5.2 hereof.（基于合同第五条第二款规定的各方在合资公司中的权益）

3.as the case may be 视具体情况而定；

as the ventures may determine视投资方决定而定

例：The venture may relocate its office from time to time or have additional office as the ventures may determine.(该合资公司视投资者决策，可随时迁址或增添营业场所）

4. as soon as practical尽快（= as soon as possible)

5. such...as突出as后的内容

例：The parties may agree to extend the expiration date to such date as is reasonable in the circumstance.（合同各方同意根据情况合理推迟合同到期日）