  Similariton-like pulses are found to be formed in synchronously pumped singly
resonant optical parametric oscillators (OPO) by numerical simulation. The
nonlinear coupled-wave equations can be reduced to inhomogeneous nonlinear
Schr\"{o}dinger equation. The signal pulses with parabola-like temporal
intensity profile and linear chirp are presented in OPO. The similariton-like
pulses in OPO have many practical and potential applications.
