SAS帮助文档是这么说的，

• %QUOTE and %NRQUOTE mask the same items as %STR and %NRSTR, respectively. However, %STR and %NRSTR mask constant text instead of a resolved value.
• And, %STR and %NRSTR work when a macro compiles, while %QUOTE and %NRQUOTE work when a macro executes.
  

谁能解释一下第二点究竟是什么意思

有点意思。。。

The macro language provides an additional set of tools to assist in:

• communicating between SAS steps,
• constructing executable and reusable code,
• designing custom languages,
• developing user-friendly routines,
• conditionally execute DATA or PROC steps.
  

It is worth mentioning that during macro compilation only macro statements are compiled, so be aware that non-macro
text and macro references are not evaluated during the compilation phase – but during macro execution .

When one macro is invoked, the SAS code is generated. This time is called macro execution time.
It is intertwined with the compiling (or parsing) of the generated SAS code. Finally there is the SAS execution time when the compiled code is executed. Thus the are four important times or stages through which the lines of a SAS program with
macros move.
1. Macro compile time
2. Macro execution time
3. SAS compile time
4. SAS execution time
Typically these times are all intertwined and going on, at the same time for different lines (or parts of lines).

%LET NAME=USERFILE.MASTER;
请问各位：这个%let语句是不是也分compile 和 execute两个阶段处理？

受教了，谢谢！

同问啊。。。所以这个帖没有答案么。。。