We study the environment design problem for biased decision makers. In an environment design problem, an informed principal aims to update the decision making environment to influence the decisions made by the agent. This problem is ubiquitous in various domains, e.g., a social networking platform might want to update its website to encourage more user engagement. In this work, we focus on the scenario in which the agent might exhibit biases in decision making. We relax the common assumption that the agent is rational and aim to incorporate models of biased agents in environment design. We formulate the environment design problem under the Markov decision process (MDP) and incorporate common models of biased agents through introducing general time-discounting functions. We then formalize the environment design problem as constrained optimization problems and propose corresponding algorithms. We conduct both simulations and real human-subject experiments with workers recruited from Amazon Mechanical Turk to evaluate our proposed algorithms.