Abstract: The traditional method of cell imaging is too much operation on the cells in the preparation work.It is not suitable for real-time observation of living cells.This experiment introduces a method of combining a large numerical aperture oil immersed dark-field condenser and a coverslip-less water immersion objective to high resolution real-time cell imaging.To minimize cell operation in the preparations for the real-time imaging，this experiment by using water immersion lens inserted directly into the Petri dish in PBS ( phosphate Physiological Buffered Saline ) or culture medium to replace the traditional cell smear and cell drop operation，to obtain adherent and suspension cultured cells real- time dark field image culture. Observation of adherent cells in PBS can get better effect in this dark field imaging system; observation of suspension cell in culture medium can be obtained， but the dark field effect.This optical system is simple and inexpensive，and can be widely used in the research work related to cells.

Key words: dark-field, water immersion objective, live cell imaging, coverslip-less