City Bike's user behavior has been a popular topic since the City Bike data is released. This research focuses on the trip duration based on gender differences used data from January 2015. After removing outliers, the distributions of men and women's trip duration are revealed. By conducting a Mann Whitney U test, men and women are verified having different trip duration distributions. Citi Bike group can then rearrange the bike distribution in the city based on gender differences of users.