An amino acid chelated calcium grade of compound amino acid powder, produced by chelating calcium with complex amino acids obtained from animal and plant protein hydrolysis. Calcium exists in chelated form with a chelation rate ≥90%, total amino acids ≥85% and calcium ≥6% (powder). Chelated calcium is highly stable and less readily fixed by soil, and can be efficiently absorbed through foliar or root application to prevent and correct physiological disorders caused by calcium deficiency such as bitter pit, blossom-end rot and fruit cracking, while supplying 17 free amino acids as both nutrient and chelating carrier. Fully water-soluble and chloride-free; compatible with most pesticides and foliar fertilisers (jar test recommended).