=VLOOKUP(MAX(A2:A20),A2:B20,2,FALSE)

The vertical look up function finds a value in the first column of your
table and will return a value from the specified column of that row. The
above formula is looking for the largest value in the range A2:A20 and
finding a match in the table that's in the range A2:B20. Then it's returning
the text from the second column (B) that's on the same row. Because we want
only an exact match, the range lookup value is FALSE.

"Eric" wrote:

There are 2 lists of value under Column A & B,
Does anyone have any suggestions on how to look up the largest value under
column B and return the value on the same row on column A.
Thank you for any suggestion
Eric