Pool and forced-convection boiling of FC-72 was conducted in earth gravity and microgravity. A thin gold-film semi-transparent heater was used to provide both uniform heat flux and measurement of the heater surface mean temperature simultaneously. Boiling curves of FC-72 at different flow rates were measured in the experiment. Flow boiling map and average bubble size vs flow rate in microgravity were obtained using photographic technique. II was observed that the forced flow would decrease the average bubble size and keep boiling in the nucleate boiling regime in microgravity. The influence of forced flow on heater surface superheat and heat transfer coefficient in microgravity were also studied in the experiment. With the increase of flow rate, it was found that the average superheat of the heater surface would decrease and the heat transfer coefficient would increase.