Dissipative soliton resonance (DSR) is a promising operation regime in fiber lasers where unlimited pulse energy boost is expected. However, several phenomena classified as anti-DSR performance were reported recently. Here pulse shrinkage of DSR pulses is investigated in a fiber laser. By setting a central-wavelength-drifting Gaussian filter, after DSR performance of pulse broadening with increasing gain, the pulse shrinkage occurs when the gain continues to increase. A central-wavelength-drifting bimodal filter can also achieve pulse shrinkage. In addition, pulse shrinkage together with period doubling can be observed by changing the initial settings.