The current study aims to Genotyping of rs12997 SNP in binding site of let-7b miRNA in ACVR1 gene using PCR-sequencing, the results found the percentage of deletion mutation in patient was 66.66% while in control group 3.7 % in highly significant differences, other study characteristic non- significantly association with rs12997 belong to the gender the deletion mutation was higher in male 41.66% than female 25%, the percentage of deletion mutation was a same percentage (10.41%) in both in Adenocarcinoma and Mucinous adenocarcinoma, in cancer grade the highest percentage was observed in well differentiated (37.5%) and moderate differentiated (29.16%), the deletion mutation appeared in all grades of lymph node metastases, in the N0 (31.25%), N1 (14.58 %) , N2 (8.33%), N1b (2.08%), N2b (6.25%) and N2a (4.16%). the highest percentage of deletion mutation observed in III and I (20.83%) , and in II ,IIA and IIIb (6.25%), According to metastasis the M1 deletion mutation was (4.16%) whlile in the Mx the deletion mutation was (2.08%) , non-sig assocation abserved between genotypes (CT, CC, and TT) between patients and control (p 1.3333, 0.3811) and also non- significant association with cancer characteristic in current study. The findings concluded that the deletion mutation was strong association with colorectal cancer but genotypes didn't effecte in colorectal cancer characteristics.