data aa;
input id class$ x y;
cards;
1 a 310 0.035
2 a 1915 0.054
3 a 949 0.068
4 b 2573 0.76
5 b 3389 0.037
6 b 1470 0.074
;
run;
proc sort data=aa;
by id;
run;
proc reg data=aa noprint;
by class;
model y=x;
output out=res p=pred;
run;
quit;
proc sgplot data=res;
series y=pred x=x/group=class;
scatter y=pred x=x/group=class;
run;

同求. Excel用什么画2条回归？

Here is an example.

proc sgplot data=sashelp.class;
  reg x=height y=weight / LEGENDLABEL= "height-weight";
  reg x=height y=age / LEGENDLABEL= "height-age";
run;

准确的说，excel那叫趋势线，画两组散点图，然后可选添加趋势线

beautiful!
我总是想不到把结果输出之后再来用，多谢指教哈！