[Purposes] This paper investigates data policies made by Chinese scientific journals, so as to study data policies and provide references for Chinese journals in drafting and improving their data policies. [Methods] Based on 65 SCI-indexed journals sponsored by Chinese Academy of Sciences, this paper analyzed these journals' data policies in terms of data submission, data review, data deposition, and data citation by investigating their author instructions on their websites, as well as the intensity of these data policies. [Findings] Among all sample journals, 37 journals (57%) publish their data policies. Most journals (84%) encourage data sharing while a few journals (16%) carry out mandatory policies. These journals make their policies based on their overseas partner publishers' policies and their data policies cover data submission, review, deposition, and citation. Only a few journals have data review policy. These journals are lack of the specification and description of data related rights and interests, such as copyright ownership and data usage and licensing agreements. [Conclusions] Chinese scientific journals should pay attention to formulating and improving data policies that are suitable for their development and disciplinary development according to their own situation. Their data policies should specify data submission, review, deposition, and citation, and build the protection mechanism of data related rights and interests. Government bodies, research funders, and journal editors should all attach importance to the research of data policies and scientific data sharing, and make policies and take measures.