In sentiment analysis (SA) of product reviews, both user and product information are proven to be useful. Current tasks handle user proﬁle and product information in a uniﬁed model which may not be able to learn salient features of users and products effectively. In this work, we propose a dual user and product memory network (DUPMN) model to learn user proﬁles and product reviews using separate memory networks. Then, the two representations are used jointly for sentiment prediction. The use of separate models aims to capture user proﬁles and product information more effectively. Compared to state-of-the-art uniﬁed prediction models, the evaluations on three benchmark datasets, IMDB, Yelp13, and Yelp14, show that our dual learning model gives performance gain of 0.6%, 1.2%, and 0.9%, respectively. The improvements are also deemed very signiﬁcant measured by p-values.