The study of Factors influencing the consumer buying decision toward smart phone in Udonthani Municipality. The objective To study the use of mobile smartphones. And to investigate the factors influencing the decision to purchase mobile smart phones, consumer Udonthani Municipality.The population of the study is that consumers using mobile smart phone in UdonThani Municipality. Determine the sample size by using the formula of the neck Cranbrook (Cocran) is number 400 people were analyzed using descriptive statistics including the frequency of maximum and minimum deviation and statistical t-test f-test.