hi Anahita,  take a look in the next link https://www.researchgate.net/post/How_can_I_get_the_percent_of_crystallinity_from_Powder_XRD_data

i didn't understand. how do i fit  of XRD peaks by gaussian or lorentizan function?

and then how i get % crystallinity? :(

Select the respective spectrum in the software and the apply the Gaussian or Lorentzian fitting function.

To find out the percentage crystallinity, you have to compare with the standard.