Graphene has attracted wide attention and been believed to be an ideal saturable absorber due to ultrafast saturation recovery time, wide absorption band, low loss, low cost, easy fabrication, super mechanical properties and high thermal conductivity. This paper presents our progress on grapheme preparation and its application in solid-state lasers. The high-quality graphene sheets with lateral size over 20 μm are obtained by bath-sonicating after processing the worm-like graphite marginally with mixed oxidizer. With graphene as saturable absorber, 16 ps pulses have been obtained from the mode-locked NdGdVO4 laser, with an average output power of 360 mW and a pulse energy of 8.4 nJ. By employing YbKGW crystal as gain medium, we have also obtained 489 fs pulses with an average output power of 564 mW.