Development and production of antibacterial materials were gained momentum because of the increasing infectional diseases in recent years. Antibacterial products are used in many industries, such as, textile, dye and package industries and medical technology. Short duration antibacterial affect is the main problem for these products. Therefore, the development of materials that exhibit long duration antimicrobial activity, is needed for industry. In this study, the free carboxylic acid groups of alginate were activated using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and amoxicillin (AMX) was covalently immobilized to alginate. AMX, D-alpha-amino-p-hydroxybenzyl penicillin trihydrate, is one of the most frequently used beta-lactam antibiotics that has been employed to treat and reduce the spread of bacterial infections in human, with the benefits of maintaining animal welfare. At the end of the study, an antibacterial biomaterial was developed. The optimum reaction medium, that immobilization of AMX to Ca-alginate beads, was determined as; 1 mg of EDC, pH 5, 50 mM of phosphate buffer, 5 pieces of Ca-alginate beads, incubation temperature was 4 degrees C, mixing speed was 150 rpm, initial amount of AMX (IAA) was 4 mg and incubation time 1.5 h. Ca-alginate beads and AMX immobilized Ca-alginate beads were tested for antibacterial affects against Escherichia coli (ATCC 8739, gram negative) and Staphylococcus aureus (ATCC 6538, gram positive) bacterial strain. According to the SEM images and ATR-FTIR spectrums of AMX immobilized Ca-alginate and Ca-alginate beads were analyzed, the immobilization process was proved successfully. Developed biomaterial was antibacterial according to antibacterial tests. (C) 2016 Elsevier Ltd. All rights reserved.