In some places, bicycles are considered as one of the transport tools, and riding there is for function, while in some other places, bicycles are taken as physical activity, and thus riding there is for leisure. Riding for leisure or for function? 450 recreational cyclists from bicycle clubs and bicycles activities were sampled using convenience sampling, and there were 392 valid questionnaires or 89.2% of the sample. A self-developed questionnaire was administered to the respondents. This research firstly dealt with the relationship between recreational bicycling and bicycle commuting, second, the motivations and constraints of bicycle commuting were investigated, and finally, bicycle commuting policy was proposed. After the descriptive statistics analysis and Chi-square test, I concluded that there were strong connections between recreational bicycling and bicycle commuting, 38.5% of recreational cyclists also choose bicycle commuting. The motivations for bicycle commuting were enjoying riding bicycle, improving fitness, saving fuel, being environmentally-friendly, controlling weight, and commuting distance was short. The constraints to bicycle commuting were climate, lack of bikeways, bicycle theft, poor air quality, bad pavement, and safety. It is possible to encourage more cyclists to commute with bicycles by cycling awareness programs and better bicycling policies. The Taiwanese government should utilize the advantages of bicycle commuting, and promote cycling in Taiwan, not just for recreational purposes, but also for bicycle commuting purposes.