Today, the costumer is the key to success or failure of a company, so examination of factors affecting the behavior of costumers, especially the intention of buying, is important. One of these buying behaviors that plays a key role in maintaining market equilibrium is the unplanned buying behavior which is decision making at the moment. In this study, factors affecting the unplanned buying behavior (entertainment) are considered in social networks. Then, the conceptual models, based on the data from 384 participants who had experienced online purchasing on the Instagram, were analyzed using AMOS software. The validity and reliability of the instrument were evaluated and proved. The results showed that elements such as enjoyment of similarities and expertise, visual and interactive attractions spread a positive impact on enhancing the tendency to unplanned buying. In addition, hyper-social interactions had positive impact on the tendency and willing to go for impulsive buying.