thank you Mahdy for suggestion , i got the answer to measure the area but still how can i measure the volume of white and grey matter? 

once you have the area, assume the thickness is constant in each slide and multiply the area by the thickness of the slide.

What histological staining are you using?

The right choice could make a big difference

thank you Jim Macdonall, actually i am planning to quantify the white matter and grey matter not in histological slide  but in photograph of coronal section of brain. but any way i think i can take the thickness of slice to measure the volume.

To Patric J Gannon.

can,t we measure on gross coronal section without staining ?

You have to stain your sections using silver nitrate or crystal violet as an example which will emerge your area which will be used through the threshold of the ImageJ or even photoshop

thank you Hafez

can i use HE stain to measure the area of white and grey matter ?

I did not use it before to reveal with HE as it shows only the structural shape of brain and so, may be

I think Luxol Fast blue is a good candidate to stain the white matter but HE is helpful for nucleus and cytoplasm staining

Yes. You can use it after adjustment for size and shape.

Good luck

Of course, you can. You just have to do simple calibration and then proceed.

I'm currently using ImageJ analysis software for my study. I'm using a stage micrometer for calibration purpose. You can borrow it from me...

thank you Ashok Ayer and Marla sir.

Marla Sir I also need that software.

You can download it from the official website: http://rsb.info.nih.gov/ij/download.html

The software varies according to your system configuration. So you need to match that first and then download.

Definitely you can...But you should calibrate it beforehand.