The methodological model for social research is physical science conceived in terms of the logic of the experiment. However, ethnography was sometimes dismissed as quite inappropriate to social science on the grounds that data and findings it produces are subjective. Hence, ethnographic research is the role to learn more about buyer behavior through marketers may have been listening more to consumers ( e.g. through qualitative research), efforts have almost always been directed at controlling consumers ranges of products or services predetermined by producers have been pushed through with littler real involvement of consumers in the process at a time in which consumers are ever more aware of what is being done to marketers. To seeing consumer's daily life behavior can predict why who choose to buy your or your competitor's product. Then, the product manufacturer can judge what the reasons are caused to attract the consumer chooses to buy the product to use. Hence, the data analysis procedure will include these steps as below: ⦁First step, Facial expression videos camera record activity; input data from given tasks will be carrying on researching at the same time.⦁Second step, the feature extraction will be caused⦁Third step, the chi-square feature selection will be caused⦁Fourth step, the machine learning training will be caused⦁The final step, the results of behavioral prediction and data classification will be output at the same time.⦁Why ethnographic research can be predicted consumer's behavioral performance to detect emotion by video recording camera at home ? Ethnographic field research involved the study of groups and people as go about every day lives. There has two distinct activities. First the ethnographer enter into a social setting and gets to know the people and observes all the approach. But second the ethnographer writes down regular systematic ways what who observes and learns when participating in the quality rounds of life of others. Thus, the researcher creates an accumulating written records of these observations and experiences. Two interconnected activities comprise the care of ethnographic search: participation in some initially familiar social world and the production of written accounts of that world by drawing upon such participation. Hence, ethnographers are committed to get close to the activities and everyday people. Getting close minimally requires physical and social proximity to the daily rounds of people lives and activities, the field researcher must be able to take up positions in order observe and understand whom. Consumer behavior refers to the behavior that consumers display in searching for purchasing, using, evaluating and disposing of products and services that who expect will satisfy their needs and it's behaviors that are directly involved in the action of obtaining, consuming and spending products or services, including the decision processes that precede and follow these actions. It seems ethnographic research can helps the marketer to understand how consumer think, feel and select from alternative like products, brands and the like and how the consumers' buying behaviors are influenced by their environment, the reference group, family and salespersons.