The pressure effects on magnetic properties of one-dimensional Mn complexes with 1,3-bis(N-tert-butylaminoxyl)benzene and 5-chloro-1,3-bis(N-tert-butylaminoxyl)benzene have been studied. These complexes have weak interchain interactions with different signs and the former is a metamagnet and the latter is a ferrimagnet at ambient pressure. The interchain interactions of the former is enhanced by pressurization. The transition temperature becomes higher and the critical field becomes larger with applying pressure. The closer spacing of each chains caused by pressurization, yields larger antiferromagnetic interchain interactions in this compound. On the other hand, the response to the pressure of the latter ferrimagnet, is rather complicated. The transition temperature becomes higher and the antiferromagnetic interchain interactions are induced by pressurization. The interchain exchange coupling in this compound should be sensitive to the relative orientation of the chain structure. The decrease of the ferromagnetic contribution and/or the increase of the antiferromagnetic one in the interchain interactions is brought about by pressurization.