During the past five years, 6, 7, and 26 transit observations were carried out for the HAT-P-9b, HAT-P-32b, and HAT-P-36b systems, respectively, through the Transiting Exoplanet Monitoring Project network. Combined with the published photometric data and radial-velocity measurements, our new photometry allows us to revisit the system parameters and search for additional close-in planetary companions in these hot Jupiter systems. We measure an updated RP/R*？=？0.1260？±？0.0011 for HAT-P-36 system in the R band, which is 4.5σ larger than the published i-band radius ratio of 0.1186？±？0.0012. We also perform a transit timing variation (TTV) analysis for each system. Because no significant TTVs were found, we place an upper mass limit on an additional planet for each system.