When I shoot in jpeg and post posses in Cs4, and save, the file come out at about 1.3 megs ,even at max quality.
seem to be the same as if I were saving fo web
Is this right or am I doing some thing wrong?

You'd have to tell us what post processing you were doing. I'm no PS expert but I suspect that you resized/resampled the image and hence thrown away many of the pixels. 1.3MB seems way too small for a maximum quality / minimum compression jpg file from a modern camera that has 10 MPx or more.

- Alan

Did you crop the image?

Yes I do crop the images,but I've croped some a very small amount and some a lot like 100+
the size of the files only change's like from 1.3 to 1.7, if I don't crop the file stays the same about 7 mb

How is the jpeg quality set on your camera? Sounds like you have the camera set for low quality jpeg.
the other problem could be that you are cropping and you have the crop set to a small size.

Tom