Objective To investigate the therapeutic results of first and second generation PDL for port wine stain（PWS） and compare its difference.Methods Fifty patients（range 17-59 years） were treated with first and second generation of PDL.First generation of PDL was featured wit wave length 585 nm,5 mm spot size,pulse width 0.45 ms at frequency 5-6.5 J/cm2.Second generation of PDL was featured with wave length 595 nm,5 mm spot size,pulse width 1.5-3 ms at fluences 11-12.5 J/cm2,DCD was used dynamic cooling duration 20 ms,delay 20 ms.Results Based on chi-squared analysis,there was no statistically significant differences between first and second generation of PDL.Conclusion There was no significant difference of clinical outcome between the first and second generation PDL for the treatment of PWS.Cryogen spray cool equipment of second generation of PDL can improve the safety of PDL effectually.