Abstract: In order to study the dynamic characteristics of self-similar pulse-pairs in dispersion decreasing fiber, the evolution and compression of pulse-pairs were simulated theoretically with nonlinear Schrdinger equation. In addition, the interactions between the pulses in the neighboring region were analyzed. The results show that without considering the third-order dispersion, the symmetrical oscillation is created in the overlap region while the evolution of pulses is unaffected outside the overlap region. After dispersion compensation, the compressed pulse-pairs are obtained with the temporal width of 128.4fs and the compression factor of 7.8. When considering the third-order dispersion, the evolution of pulses is distorted and created asymmetrical oscillation in the overlap region. The compressed pulse-pairs have a temporal width of 211.6fs and the corresponding compression factor of 4.7. It is worthy of noticing that the pedestals of compression pulse due to asymmetrical oscillation do not affect the quality of the pulses severely. The results provide references for the evolution of self-similar pulse-pairs.