x2+y2-2mx-2my+2m2+m-1=0可化为(x-m)2+(y-m)2=1-m∵集合{(x,y)|x2+y2-2mx-2my+2m2+m-1=0}表示圆,∴1-m>0∴m<1故答案为:{m|m<1}