Modern observations have demonstrated two kinds of correlation between tropical Sea Surface Temperature(SST)and local precipitation anomalies: negative in Asian-Pacific summer monsoon regions and positive in Central-Eastern equatorial Pacific. The new global LGM SST reconstruction from MARGO(Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface project) is used to validate the sensitivity of tropical rainfall to SST variations under different climate backgrounds. And more, the SST outputted from the LGM simulations of Atmosphere-Ocean (AO) coupled model (CCSM 3) can be used to assess the reliability of MARGO SST reconstruction and the two kinds of relationship from modern observations.