Curcumin was incorporated into oil/water (o/w) emulsion by dissolving it in soybean oil to cover the surface of the oil droplets with a pH-sensitive polyelectrolyte complex (PEC) composed of chitosan and fucoidan molecules. This curcumin-loading efficiency of the suspension system was investigated. The size and zeta potential distributions of novel curcumin-loaded chitosan nanoparticles self-assembled with fucoidan (CFNPLC) were assessed at various pH and fucoidan-to-chitosan mass ratio (FCMR). The release behavior of curcumin from CFNPLC was confirmed quantitatively by the superimposition of relevant release behavior. The release of curcumin from CFNPLC prepared with a chitosan solution of pH 6 for one to two days was slower than that from CFNPLC prepared with a chitosan solution of pH 3.7 for five to 10 hrs. This was attributed to the higher affinity of a chitosan molecule to curcumin molecules at a higher pH. The centrifugation of release medium accelerated the release of curcumin droplet from the surface of CFNPLC into the release medium much faster than a conventional curcumin release. Not to mention a high stability of curcumin blended with soybean oil, encapsulated in CFNPLC, the advantage of the CFNPLC is addressed in such a way that curcumin releasing period of a conventional curcumin delivery using CFNPLC, is supposed to be extended for much longer time than one to two days of the curcumin release period in this study. Thus, CFNPLC can bring about an enhanced effect of curcumin bioavailability resulting from the high curcumin stability and its extended release because it was dissolved in soybean oil and CFNPLC sustained slow curcumin-release for more than days in the oral drug (curcumin) delivery system. Therefore, CFNPLC can be treated mainly as a food-functional additive or healthy dietary product for tumor patients.