iam currently using athlon xp 1500+.my cpu temp is within 57 - 64 celcius and my casing temp are below 40c.Is this normal? are these cpu temp depend on room temperature or temp in casing (including devices in use;hd,cd drive, psu & etc.

Those temps should be 40-50C. A good HSF with thermal paste is the best tweak to improve things.

Those temperatures are just fine as long as your system is 100% stable. Loop 3Dmark 2001 for several hours just to make sure. Otherwise I wouldn't worry about it, people will tell you things like get it into the 40's, but not everyone wants a HSF that sounds like an F16 fighter plane taking off. I got mine into the high 40's on idle but that's with a new HSF (I put on a quiet 5800RPM CPU fan to replace the 70000RPM delta which was ridiculously loud) and 5 extra case fans. Again if your system is stable it's probably fine, but you can always look into case fans which will help a bit and keep your components cool which is important for their longevity.

the system temp is a sensor on your motherboard. the cpu temp measures the cpu only. My case has a digital thermometer on its face, and inside there is a probe that is touching the cpu. The probe and the cpu temp program are usually only 2 degrees off (sometimes it's 1 degree off)

Yes room temperature has a lot to do with it.Your CPU temp is high because your case temp is high because your room temp is high????Look at your case fans and the airflow inside the case.try to keep your wiring neat and tidy and out of the way of the airflow.I am using a AMD 1.4T'bird overclocked (145x11)with normal AMD HSF plus intake fan and exhaust fan running right now with a room temp of 24c at 48c and a case temp of 28c.Its summer where I am at with a 35C today.During the cooler months my temps drop by about 4c.

57 - 64 celcius is no problem at all, im running my 1800+@65-70 celcius. I think the critical temp is around 90. i running my cpu fan in silent mode, hate the noise.