Abstract: Uniaxial compression tests were performed on the steel fiber reinforced concrete (SFRC) specimens with different ages and steel fiber volume fractions. The acoustic emission (AE) and microseismic (MS) signals were monitored during the loading progress. Through the in-depth analysis of testing results, the feature of AE and MS signals and the evolution of crack propagation in SFRC were studied. The results show that: (1) The crack propagation of SFRC during uniaxial compression can be divided into four stages: Crack compaction stage (I), crack stable development stage (II), crack unstable propagation stage (III) and post-peak failure stage (IV). Different stages show different AE and MS characteristics. (2) With the increase of age, the energy rates and count rates of AE and MS in stages I and II decrease, as well as the generation rates of micro-, meso- and macro- cracks of the whole specimen. However, the energy rate and count rate of AE and MS in stages III and IV increase, as well as the generation rates of micro-, meso- and macro-cracks of the whole specimen increase. (3) With the increase of steel fiber volume fraction, the AE energy rate, AE count rate and micro-crack generation rate of the whole specimen in stages II, III and IVincrease, while the MS energy rate and MS count rate in each stage decrease, and the MS energy surge time rate in each stage increase. Furthermore, the generation rates of meso- and macro- cracks of the whole specimen in each stage decrease, and the failure time is delayed. (4) Before the failure of SFRC, the energy rates and count rates of AE and MS increase sharply, as well as MS energy ratio. These variables can be used as the precursor index of SFRC failure.