Fertilizer is majority expenditure of agriculture, however, Thai farmers faced counterfeit and expensive fertilizer. There is limited only formula fertilizers available in the market. To help farmers increase productivity and able to identify the propoerties of soil, in 1997 Dr. Tasnee Attanandana had researched a site-special nutrient management (SSNM), or called “Tailor-made fertilizer”. In term of technology transfer, Dr. Prateep Verapattananirund disseminated a soil test kit to the public but the adoption rate was slow. Base on this circumstance, this study analyzes the factors affecting farmers’ decisions by using Technology Acceptance Model (TAM) to measure the acceptance of a soil test kit. The study is conducted by using quantitative research, with 100 Thai farmers and concludes that social influence is not affect. Compatibility and training are influence to perceived usefulness while compatibility, trust and training are influence to perceived ease of use. Herein, perceived usefulness, perceived ease of use, and attitude toward using are influence to usage intention of a soil test kit. This result can also be used as a guideline for adoption plan of soil test kit technology.