Background: The Natural killer cell activity measurement test of the ELISA method developed by company A could have many economic benefits in terms of cost and time compared to the existing 'cytotoxicity test method'. A portable incubator capable of culturing the specimen while moving was developed as a way to save test time and secure the stability of the specimen when transferring the specimen to the entrusted institution. Objectives: This study investigated efficacy evaluation of NK cell activity measurement in a portable incubator. Design: Experimental research. Methods: 100 participants were selected to measure NK cell activity. The collected blood was placed in a general incubator and a portable incubator at the same time to start culturing, and the plasma was separated by centrifugation. The NK cell activity test was measured by enzyme immunometry. Results: In the verification of the culturing performance of the developed portable incuvator, no significance was found between the general incuvator and the portable incuvator, and the same performance was maintained in culture. Conclusion: Portable incubators have a great effect on shortening the test time and securing the stability of samples.