Two bromine substituted indole chalcone derivatives were synthesized via typical condensation reaction between 2-(hydroxyl)-4-bromine acetophenone and 3-indolealdehyde (1) or N-ethyl-3-indolealdehyde (2) in good yields. Their recognition properties for cyanide anions were investigated. The results indicate that the compounds exhibit quick and obvious color and fluorescence turn-on changes to cyanide anions with color changes from yellow to red (1) or from light yellow to deep yellow (2). Mechanism studies suggest that hydrogen bonding reaction between cyanide anions and N-H moiety of compound 1 occurs, which leads to the red shift of absorption spectra and the deepening of color. To compound 2, bonding mechanism is typical Michael reaction mechanism. (C) 2016 Elsevier B.V. All rights reserved.