Abstract: To study the effect of different culture media on cell morphological characteristics, DNA, biomass growth and huperzine A content in in vitro cultures of Huperzia serrata. In the different culture media, named Sh, W, and Shx, H. serrata differentiated into thallus, rhizomorph and mossy culture, respectively. The single cell developed into clusters and split to form tissue. Roots and rhizoids developed on rhizomorph and mossy cell surface more than on thallus. The total DNA content differed. The morphologic changes may be related to apoptosis because mossy culture showed a DNA ladder after 35, 45 and 55 days. Biomass increase was measured for thallus (1 788±31)%, rhizomorph (833±27)%, and mossy culture (1 963±52)%, and huperzine A content was 71.7±1.54, 20.1±0.82 and 0 μg·L^-1, respectively, with significant differences (P<0.01) among the 3 morphologies. Thallus grew slower than did mossy culture, but huperzine A content was the highest, and mossy growth was the fastest but produced no huperzine A content. The medium can lead to different forms for the same genotype in H. serrata, with changes in growth rate and huperzine A content. Thallus is the best form for producing huperzine A.