In this paper,by referring to the concept of coupled memristors (MRs) and considering the flux coupling connection,the constitutive relations for describing the coupled memcapacitors (MCs) are theoretically deduced.The dynamic behaviors of dual coupled MCs in serial and parallel connections are analyzed in terms of identical or opposite polarities for the first time.Based on the derived constitutive relations of the two coupled MCs,the modified relaxation oscillators (ROs) are obtained with the purpose of achieving controllable oscillation frequency and duty cycle.In consideration of different parameter configurations,the experimental investigation is carried out by using practical off-the-shelf circuit components to verify the correction of the theoretical calculation with numerical simulation of the coupled MCs and its application in ROs.