This paper aims at the design of a modular robot called "MiniQuad I" which is reconfigurable both in leg and body. MiniQuad I is composed by three kinds of essential modules, which are joint modules, leg modules and the body module. It can be reconfigured into variety configurations, including quadruped and hexapod configurations for different tasks by changing the layout of modules. Critical design considerations when considering the adaptability, maintainability and extensibility simultaneously are discussed and then detailed designs of each module are presented. A prototype of MiniQuad I is built and a biomemitic controller is applied to exam the reconfigurability by using those modules. Simulations and experiments on crawling and object picking are performed to verify functions of the MiniQuad I.