Abstract: On the basis of the pressure correcting method about the measurement of bubble size distribution a photoelectrical capillary probe technique with a micro-computer on line was successfully used to study in detail the effects of various operating parameters such as gas rate, feed rate, feed concentration, NaCl concentration in solution, gas bubbler and gas bubbling state on bubble and foam bubble size distributions in foam fractionation column. According to these experimental results quantitative models for foam drayage and relationship among superficial gas velocity, gas hold-up in bubble zone and surfactant concentration were obtained. The results above will further be employed in the design calculations of the foam fractionation column.