In the present study, we prepared poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, PCEC) nanomaterials by solvent-extraction method. The obtained PCEC nanomaterials were studied extensively for acute toxicity and genotoxicity using bacterial reverse mutation test (Ames test), chromosomal aberration test and mouse micronucleus test. All of the Sprague-Dawley rats did not show any mortality and clinical signs of toxicity after intravenous injection at the level of 2.4g/kg body weight. Thus, the LD(50) of PCEC nanomaterials was determined to be greater than 2.4g/kg. In Ames test, PCEC nanomaterials were negative in Salmonellatyphimurium strains TA97, TA98, TA100, TA102, and TA1535 with or without metabolic activation. PCEC nanomaterials did not induce chromosomal aberrations in cultured Chinese hamster lung cells up to 5000mug/mL with or without metabolic activation. Micronucleus assay demonstrated that PCEC nanomaterials did not significantly increase micronucleated polychromatic erythrocytes (MNPCE) in the bone marrow of ICR mice or suppress bone marrow, indicating they did not cause chromosome aberrations. In conclusion, our results indicated that PCEC nanomaterials did not cause any acute toxicity and genotoxicity in our experimental conditions. Its potential to be a candidate of drug carrier is worth being further investigated.