Abstract: Nonlinear displacement biases in response of single-degree-freedom-systems (SDOF) are studied, which are resulted from scaling the velocity pulse-like ground motion records. Based on dynamic time (history) analysis of SDOF systems subjected to 30 pulse-like ground motions, this work investigates the variation rules of the nonlinear displacement biases versus structural vibration period (T) and strength reduction factor (R) after scaling the earthquake records to the levels of target spectral acceleration (Sa), peak ground acceleration (PGA), peak ground velocity (PGV), and peak ground displacement (PGD). The variation trends of displacement biases are determined by log-linear regression of scattered points, and the stability of the biases under the condition of scaling different ground motion intensity measures are comparatively analyzed. The results demonstrate that the amount of displacement biases greatly depend on the scaling factor, the first-mode period of vibration, and overall strength of the structure. Reasonable scaling factor and reasonable ground motions intensity measuring parameter of the velocity pulse-like ground motion records can effectively reduce the calculated displacement bias in structural earthquake responses.