Disclosed is a method of preparing anisotropic conductive adhesives for flip chip interconnection on organic substrates, in which an epoxy resin as a binder is mixed with a conductive material and a non-conductive material at room temperature for 3 hours and then, with a coupling agent and a curing agent at room temperature for 1 hour. The anisotropic conductive adhesives are endowed with the electrical conductivity of conventional anisotropic conductive films and the mechanical reliability of an underfill used in a solder flip chip, simultaneously. The ACA shows fast hardenability and excellent coating and screening properties. The adhesive is spread over a plastic printed circuit board into which a flip chip is then brought. The flip chip and the plastic substrate can be bonded to each other using heat and pressure. Also, it is applicable for low-price flip chips and chip size packaging as well as for relevant-assembly packaging.