Objective To analyze the physicochemical properties and photothermal properties after introducing a certain proportion of phaeophorbide into polyvinyl alcohol-lipoic acid polymer.Methods The "one-step" method was adopted to synthesize the PVA27K-4 ％LA-10 ％ Pheide (PLP) polymer.The laser particle diameter tester was used to detect the particle size,polydispersity index and ζ potential of PLP nanoparticle (PLPN);the morphology was observed under transmission electron microscope (TEM);the in vitro fluorescent and photothermal properties were investigated by using spectrophotometric method and infrared thermal imager;the ovarian-cancer nude mice models were established and the preliminary in vivo experiment evaluation was performed.Results The synthetic PLP polymer could self-assembly form spherical PLPN in aqueous environment,which showed the tightly spherical structure under TEM.The average particle diameter,polydispersity index and ζ potential were (22.92 ± 9.00)nm,(0.117±0.056) and (-25.43±0.77)mV respectively.The fluorescence intensity of PLPN in PBS solution was significantly lower than that in SDS solution (P＜0.05).However,the temperature of the PBS solution of PLPN was significantly higher than that of the SDS solution after exposure to the near infrared light (P＜0.05).In the model of tumor-bearing nude mice,PLPN could targetaccumulated in the tumor site.The temperature in the tumor site was significantly increased after exposure to the near infrared light,which could kill tumor cells.Conclusion PLPN could emit red fluorescence,and could target-accumulated in tumor site and conduct the in vivo image,which has significant photothermal conversion properties in vivo and in vitro,and can effectively inhibit the tumor growth in vivo.