We reconsidered the quantum gravity description of the near horizon extremal
Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS2/CFT1
correspondence. We found that, for pure electric case, the right moving central
charge of dual 1D CFT is 6Q2 which is different from the previous result 6Q3 of left moving sector obtained by warped AdS3/CFT2 description. We
discussed the discrepancy in these two approaches and examined novel properties
of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include