Abstract: The impacts of nectar robbing on the reproductive success of plants is still controversial. The ecological consequences and mechanisms of nectar robbing can be effectively studied by using gauze bags to isolate nectar robbers and create a control treatment without nectar robbers. However, gauze bag color may interfere with pollinators because pollinators prefer flowers with a certain color. In this study, in order to screen the color of gauze bags with the least interference with pollinators, four kinds of gauze bags with different colors (black, white, red and green) were designed for bagging nectar spur. Natural nectar spurs without bagging were used as the control treatment to compare the differences in visiting frequency of pollinators and visiting duration time on single flower of Impatiens oxyanthera among five treatments in the six time periods in a day. The results showed that: (1) The visiting frequency of pollinators was significantly different among five treatments. The visiting frequency of pollinators to flowers with white gauze bag was closed to that of the control which was the highest, and the visiting frequency of black gauze bag treatment was the lowest, which was significantly different from the other four treatments. The gauze bag color had no significant effect on visiting duration time of pollinators on single flower. (2) The observation time period had a significantly effect on the visiting frequency and visiting duration time of pollinators on single flower. The most frequent visits occurred from 14:30 to 15:00 and the longest visiting duration time of pollinators was from 9:30 to 9:50 am. The results indicated that when isolating the nectar robbers, the white gauze bag had less interference on the pollinator's visiting behaviors, while the black one had the greatest interference. This study provided an important method reference for researching the effects of nectar robbing on plant-pollinator mutualisms through isolating nectar robber with gauze bag.