It has been found that the high‐Tcrf superconducting quantum interference devices (SQUIDs) with oxygen‐ion‐irradiated weak links show white noise spectrum down to frequencies of about 0.2 Hz. The observed noise at lower frequencies is Lorentzian with a characteristic time constant of about 30 s. In contrast, in SQUIDs fabricated from pre‐irradiated and thermal annealed films, the measured noise power scaled as 1/ f. This fact is explained as a result of defect generation in YBa2Cu3O7. The study can provide a new insight into the microscopic origin of the 1/ fnoise in high‐TcSQUIDs, because the observed 1/ fnoise in the high‐TcSQUID is caused by introduced defects. ©1995 American Institute of Physics.