A simplified model to simulate ultrasonic backscattered signals from biological tissues was developed in this study. Due to the limited storage and efficiency for general personal computers, the existing ultrasonic backscattering model needs to be further simplified for better applications on the fundamental researches associated with biomedical ultrasound. Born approximation and convolution principle were applied to the simplified model. This model can be used to generate both ultrasonic backscattered signals and gray-scale images for different characteristics and to be a tool for technology development and academic study in biomedical ultrasound. This study concluded that the simplified model of ultrasonic backscattering is simpler and faster to perform simulations than other models.