It is our great pleasure to edit this special section of the Joal of Computer Science and Technology (JCST).The database field has experienced a rapid growth with increasing of data.Therefore,novel technology for covering emerging databases such as network or graph analysis,spatial or temporal data analysis,search,recommendation,and data mining is required.The goal of the section is to provide state-of-the-art research issues,challenges,new technologies,and solutions of emerging databases.This section publishes seven interesting articles related to query processing,trajectory data reduction,botnet evolution,recommendation system,biclustering,and protein structure alignment.The articles are summarized as follows.