If you leave the axis scaling on automatic settings, then the scalings will
change with the data values. You can set the scalings to manual, but then
they would not fit if new data values go outside your manually specified
scale.
One option, if you want to keep the settings automatic but want the two axes
the same, would be to create an additional series in your worksheet,
spanning the minima and maxima of the series from both your primary and
secondary axes, then plot that series (as an invisible line) on both the
primary and secondary axes of your graph.
--
David Biddulph

"Daniel" wrote in message
...
I have a 2003 excel graph with 1st and 2nd series on Y axis left and
right.
I did change the scale of Y axis left equal to Y axis right when create
the
graph.
The graph is dynamic with data and some times I found the scale of Y
left
and Y right mismatch?
Why is that?
How can I make Y left and Y right scale equal no matter what data change?
IF I delete the Y right scale, is it guarantee that the scale of Y left
and Y right will be equal?
THanks
Daniel