harbal2007 or ang -

One method is to enter some more data on the worksheet for defining the new
line. Then use Chart | Source Data | Series | Add ...

Another method is to use Add Trendline (but you seem to want a horizontal
line, not necessarily a best-fit line).

You did not specify what type of chart you have (Line, XY(Scatter), ...), so
it is difficult to provide more detailed instructions.

- Mike
http://www.mikemiddleton.com

"" wrote in message
...
I have 10 column A data points and 10 column B data points. My graph is
good, but I want to add a horizontal trendline to the data points in the
middle of my columns while still showing the other data. help......
--
ang