I opened a new document and using cmyk setting with profile U.S web coated. All the colour changed when I saved it to jpg, what should I do?

convert the pic into RGB mode b4 save? ....

no, it will change also.

u try re-open ur jpg file using photoshop, see whether it change or not?

i think normal picture viewer cant support cmyk (correct me if wrong)

If the color changed when you opened the file, its your photoshop color setting that's need to be changed. BTW is the original file also a cymk? If it is a rgb file and you opened it with the cymk setting, definitely the color will change.

I dont think the color will be effected when you save a file in jpg, eps or tiff format.
Saving an image in jpg format only will reduce its quality not the color.

lol.. i guess i start to understand a little bit adi.

The adobe photoshop in my com is using profile: U.S web coated mode for CMYK. When i view it in acd see the colour change, i can't see the exact colour for my work. I wonder how to change it? I don't know how to set the preference in the acdsee there to match my original work, but when i'm using the window fax and preview program which included in winXP it turn out to be the original colour i used in my work.

Jayhan, i preview it using lousy (but very handy) window fax and preview but it showed the original colour... but it's different in acdsee...

and yaya, i started my work in cmyk...

better save into pdf format or tiff

I've had this problem before. Then I used the adobe gamma program thingy and it seems to be corrected.