Microwave-induced thermoacoustic imaging (TAI), inheriting fine resolution from ultrasound imaging with relatively low scattering and high dielectric contrast from microwave imaging, is considered a promising non-ionized hybrid approach for biomedical applications including breast cancer detection, foreign body detection, detection of renal calculi, etc. In TAI, ultrasound signals are generated from thermoelastic motions of tissue illuminated by pulsed microwave signals. Acoustic signals recorded by ultrasonic transducers located around the region of interest are then processed to reconstruct the images. Many experimental studies have been conducted, as well as numerical modeling. However, rigorous comparisons between experiment and numerical simulation are rarely reported. In this work, a TAI model involving complete EM and acoustic modeling of TAI system is described. Significant effort has been taken to keep the model parameters as close as possible to experimental conditions, including the exact microwave excitation, same sample configuration and geometry, accurate speeds of sound, and accurate ultrasound transducer response.