High-frequency ultrasound with contrast agents provides contrast enhancement for imaging, has potential for application to drug delivery, and enables local genomics research. However, high-frequency ultrasound has a significant limitation, the achievable signal-to-noise ratio (SNR)and depth of penetration. In this study, we developed a new ultrasound system that involves chirp-coded-excitation ultrasound imaging with chirped pulses as trigger signals and a cardinal frequency of 30 MHz. A chirp is a coded signal that linearly spans a frequency bandwidth B = f2−f1, where f1 and f2 are the starting and ending frequencies, respectively. A new chirped pulses with contrast agents to minimize the attenuation of energy in human tissues increased the signal-to-noise ratio (SNR) by 20 dB for high-frequency ultrasonic flow imaging of the heart of zebrafish and increased the penetration depth to 2.2 mm with pulse compression and a handmade expander. On the other hand, in a microbubble experiment, adopting various echo signal concentrations resulted in the desired distribution of different types of microbubbles. Using the system we developed, we experimentally demonstrated that the chirp-coded excitation reduces the SNR by about 43 dB compared with unipolar and bipolar pulse excitations.