In association with the mortality rate due to air pollution, vehicular emitted fine particles (PM 2.5) are a threat to public health. PM 2.5-induced in-vivo studies on environmental microorganisms can be used to assess the adverse impacts of PM 2.5 on human health. In the present study, the toxicity of traffic-related-air-pollutant (TRAP) PM 2.5 was evaluated in the animal model Caenorhabditis elegans (C. elegans) using different toxicological endpoints such as lethality, survivability (lifespan), behavioral (head thrashing and body bending), and reproduction (brood size). The TRAP PM 2.5 sample were collected in Taichung City, Taiwan from Mar 24 to April 15 in 2018. Of these 23 day samples, three samples (Days A, B, and C) were randomly selected. The results showed that no immediate lethality was observed after acute (24 h) exposure of the nematodes. On the other hand, sublethal endpoints of reproduction exhibited statistically significant dose-dependent reduction, although Day A and Day C did not decrease the egg-laying capability of the worms. For the neurological toxicity, it is inferred that the higher the PM 2.5 concentrations, the more the adverse effects of neurobehavior (head trashing and body bending) it poses on the C. elegans. The lifespans of nematodes exposed to heavily TRAP PM 2.5 were significantly shortened compared with those of untreated ones based on survival rate. The nematodes exposed PM 2.5 models not only posed potentially adverse health effects on human but also represented ecotoxic impacts on the ecosystem. In conclusion, heavy concentrations of TRAP PM 2.5 significantly and severely disrupted toxicological endpoints of neurology and reproduction to C. elegans. TRAP PM 2.5 significantly shortened the lifespan of the nematodes compared with the control. TRAP PM 2.5 might more severely influenced the specific toxic endpoints, such as lifespan and neurobehavira, in this in-vivo models compared with the reproductive endpoints.