Objective    To study the relationship between Poly(ADP-ribose) glycohydrolase (PARG) and Poly(ADP-ribose) polymerase (PARP) in colorectal carcinoma.     Methods    Immunohistochemical S-P staining was used to examine the expressions of PARG and PARP in 44 specimens human colorectal carcinoma. The positive rate of PARG and PARP in murine colon carcinoma CT26 cells was detected by flow cytometry before and after the treatment of PARG inhibitor Gallotannin.     Results    PARG and PARP expressed in colorectal carcinoma specimens was of positive correlation (r=0.300 01

P0.05). The expressions of PARG and PARP were weaker in Gallotannin-treated CT26 cells than those in the control cells (P0.05).     Conclusion    The expressions of PARG and PARP are correlated positively in colorectal carcinoma. PARG inhibitor suppresses the expressions of both PARG and PARP

indicating that PARG may regulate PARP.