The influence of particle size and content of recycled fine aggregate(RFA) as well as fly ash on frost resistance of concrete were studied by freezing thawing test. The results indicate that the frost resistance of recycled fine aggregate concrete(RFAC) is inferior to normal concrete, it is deteriorated with decreasing its minimum particle size and increasing its content. When the minimum particle size is smaller than 0.16 mm and the content is higher than 40%(by mass), the frost resistance of RFAC significantly deteriorates. The frost resistance of RFAC deteriorates with increasing fly ash content, but it is still good than that of RFAC without fly ash. This indicates that fly ash is good for RFAC to increase the frost resistance.