Extremely abundant trace fossils are associated with the deep-sea deposits, especially in turbidite measure and flysch facies. And these trace groups then become the effective indicators to reconstruct the ancient depositional environment and the palaeogeography. This paper focuses on ( ⅰ ) the formational features of deep-sea fossil and its assemblage feature, and further recongnizes that the coexistence of the shallow and deep water trace group in a depositional sequences is the identification mark of turbidite sequence; ( ⅱ ) thought and methods using the trace fossil to restore their environmental parameters such as the ancient sea depth, oxygenbearing condition and sedimentation rate, etc.; ( ⅲ ) the application and significance of deep-sea ichnofacies in environment interpretation. Extremely abundant trace fossils are associated with the deep-sea deposits, especially in turbidite measure and flysch facies. And these trace groups then become the effective indicators to reconstruct the ancient depositional environment and the palaeogeography. This paper focuses on (i) the formational features of deep-sea fossil and its assemblage feature, and further recongnizes that the coexistence of the shallow and deep water trace group in a depositional sequences is the identification mark of turbidite sequence; (ii) thought and methods using the trace fossil to restore their environmental parameters such as the ancient sea depth, oxygenbearing condition and sedimentation rate, etc .; (iii) the application and significance of deep-sea ichnofacies in environment interpretation.