The best tracks and satellitesborne infrared cloud top temperatures (TBB) observations of the National Centers for Environmental Prediction Final Analysis are employed to examine the largescale and innercore convection and characteristics of tropical cyclones (TCs) undergoing different intensity changes in the western North Pacific (WNP) and South China Sea (SCS) ocean basins from 2000 to 2014. The mean conditions of TCs cases that undergo rapid intensification (RI) are compared to those of the nonRI cases. In addition, the nonRI cases are defined in four other intensity change bins: slow intensification (SI), intensification stable (IS), slow weakness (SW) and rapid weakness (RW). For the environmental variables, statistically significant differences are found between RI cases and nonRI samples, especially in IS, SW and RW groups. In both basins, RI events tend to form in environments with weaker environmental vertical wind shear than SI cases. In the WNP, RI events occurred in high maximum potential intensity environments characterized by warmer sea surface temperature, greater upperoceanic heat content, and stronger upperlevel divergence. RI events tend to occur in favorable environments with higher lowerlevel relative humidity, and cooler upperlevel temperatures than nonRI cases. For TBB observations, RI cases have larger cold TBB covering areas in the innercore regions, and lower average symmetry TBB within the eyewalls of the storms. The KNearest Neighbor (KNN) rule is employed to identify the RI cases using leaveoneout cross validation. The results show that the verification of forecasts is generally skillful.