Abstract: Di-2-ethylhexyl phthalate (DEHP) is used as a plasticizer commonly and exists widely in environment.The effects of early D-shaped veliger larvae development and embryonic DNA damage of Pinctada martensii exposure to DEHP were studied in this report.The results showed that DEHP had a significant effect on the development of D-shaped veliger larvae.There was a positive correlation between mortality rate of D-shaped veliger larvae and exposure time of DEHP in a same concentration group.In the concentration groups of (4~32 )mg/L,there was a significant dose-response relationship between the larval mortality rate and exposure concentrations at different exposure time.It can be concluded that DEHP exposure caused adverse effects on the development of D-shaped veliger larvae and may also influence the population structure of Pinctada martensii.DEHP exposure induced DNA damage of embryo cells significantly.There was a good dose-effect relationship between DNA migration and DEHP concentrations.Tail length (TL),tail DNA content (T-DNA) and olive tail moment (OTM) increased significantly with exposure concentration.The results indicated that developmental and morphological changes of D-shaped veliger larvae and the DNA damages in embryo cells of Pinctada martensii could be used as sensitive biomarkers of DEHP exposure in the marine environment.