  Click-through rate~(CTR) prediction, whose goal is to estimate the
probability of the user clicks, has become one of the core tasks in advertising
systems. For CTR prediction model, it is necessary to capture the latent user
interest behind the user behavior data. Besides, considering the changing of
the external environment and the internal cognition, user interest evolves over
time dynamically. There are several CTR prediction methods for interest
modeling, while most of them regard the representation of behavior as the
interest directly, and lack specially modeling for latent interest behind the
concrete behavior. Moreover, few work consider the changing trend of interest.
In this paper, we propose a novel model, named Deep Interest Evolution
Network~(DIEN), for CTR prediction. Specifically, we design interest extractor
layer to capture temporal interests from history behavior sequence. At this
layer, we introduce an auxiliary loss to supervise interest extracting at each
step. As user interests are diverse, especially in the e-commerce system, we
propose interest evolving layer to capture interest evolving process that is
relative to the target item. At interest evolving layer, attention mechanism is
embedded into the sequential structure novelly, and the effects of relative
interests are strengthened during interest evolution. In the experiments on
both public and industrial datasets, DIEN significantly outperforms the
state-of-the-art solutions. Notably, DIEN has been deployed in the display
advertisement system of Taobao, and obtained 20.7\% improvement on CTR.
