We studied the responses of Xanthium italicum seed germination to the environmental factors temperature, light, soil moisture, soil salinity, and soil pH. Our results showed that X. italicum seeds were highly tolerant to environmental fluctuations. The seeds germinated at 10℃ to 35℃ with 25℃ being the optimal temperature. The germination percentage was higher than 93% under both light and dark conditions, suggesting that light was not strictly required at the germination stage of X. italicum. Many seeds germinated at 30%-100% relative soil humidity, suggesting that X. italicum seeds also had a strong tolerance to soil moisture. The germination percentage decreased with the increase of soil salinity. However, even with a high salinity of 280mmol/L NaCl, one-third of the seeds still germinated. Most seeds were able to germinate in a wide range of soil pH values, and the germination percentage was above 90% with soil pH 4-10. These results showed that X. italicum had strong adaptability to temperature, light, soil moisture, soil salinity and soil pH in the germination stage. Our results suggested that X. italicum seeds can germinate energetically in a wide variety of drastically different habitats such as frigid high-altitude mountains, hot basin desert, open terrain, forest canopy, arid desert, humid river valley, saline-neutral soil and alkali soil. Considering this species is a serious ecological hazard and the universality of its suitable habitats, we recommend strict monitoring for X. italicum in all habitat types and eradicating this alien plant immediately when it is found.