你应该写成·：
PROC   GLM    DATA = HW2.data;


      CLASS    SEX_Z_ (REF = "0");


      MODEL    SBP_Y_ = AGE_X_ SEX_Z_/SOLUTION;


RUN;

谢谢，我是想知道REF = "0" 这个0是和什么比较，solution 放在这里什么意思

ref='0' 是不是Male？ （male ='0' , female=1?）.

我搜的：
Options :SOLUTION --Produce parameter estimates
SOLUTION  
  produces a solution to the normal equations (parameter estimates). PROC GLM displays a solution by default when your model involves no classification variables, so you need this option only if you want to see the solution for models with classification effects.

thanks