The ultrastructure and the dynamic expression of the centrin and tubulin during spermatogenesis of the fern Ceratopteris thalictroides were observed using the TEM technology and immunofluorescence technology. The present investigation shows that: (1) there are abundant radial microtubules around the early blepharoplast. The function of the radial microtubules may be used to converge mitochondria to the blepharoplast. (2) Immunofluorescence observations show that centrin is only located in the blepharoplast, basal bodies and flagellar band. The fluorescence labeling of centrin becomes brighter from the blepharoplast stage to the basal body stage. Then the fluorescence labeling of centrin becomes weak gradually with the formation of flagella and almost disappears at the spermatozoid stage. (3) The early fluorescence labeling of tubulin, showing the same form as the centrin labelling, is located in the blepharoplast, basal bodies, flagellar band. Then the fluorescence labeling of tubulin becomes more and more stronger as the flagella form in the spermatids. Based on the expression features of centrin and tubulin, it can be inferred that centrin is one of the organizer of the motile apparatuses, but not to be the components of the motile apparatuses. The main function of centrin may take part in formation of the centrioles, basal bodies and flagella of the spermatids.