I wanted to see a particular sequence in our re-sequencing data using IGV. However the .bam file is too big (10Gb) to handle. Since I am interested in only a small region in the genome, I wondering if there is any way to generate a .sam/.bam file only for that region. Thank you very much in advance!

Chenglin
This has been answered many times before. You can specify a small region of your interest and create a small bam file as shown.

    samtools view -bh chr1:100-200 > small.bam