set data work.one;
多了个 data 关键字
正确的程序应该是：
data work.one;
input  X Y $ Z ;
datalines;
1 A 27
1 A 33
1 B 45
2 A 52
2 B 69
3 B 70
4 A 82
4 C 91
;

data work.two;
set work.one;
by X Y;
if First.Y;
run;
proc print data=work.two noobs;
run;

set data work.one;
多了个 data 关键字

data work.one;
input  X Y $ Z ;
datalines;
1 A 27
1 A 33
1 B 45
2 A 52
2 B 69
3 B 70
4 A 82
4 C 91
;

data work.two;
set work.one;
by X Y;
if First.Y;
run;
proc print data=work.two noobs;
run;

谢谢 错误好低级啊