(1)∵A={x|x2-2x-3≤0},B={x|m-2≤x≤m+2}.∴A={x|x2-2x-3≤0}={x|m-1≤x≤3}.∵A∪B=A,∴B?A,即 m-2≥-1 m+2≤3 ,∴ m≥1 m≤1 ,即m=1.(2)∵B={x|m-2≤x≤m+2}.∴?RB={x|x>m+2或x<m-2},∵A??RB,∴m-2>3或m+2<-1.即m>5或m<-3,即实数m的取值范围是m>5或m<-3.