Female gametophyte development of Sinopodophyllum hexandrum (Berberidaceae) was studied on materials from different altitudes. The plant displays diversity in the megagametogenesis, and two categories of four female-gametophyte development models are observed, including the monosporous Polygonum-type, a new Sinopodophyllum type (and its two variants), which is intermediate between the monosporic and bisporic types. The results suggest that the Polygonum type is more primitive than the other types, and that the Sinopodophyllum type is intermediate between the Polygonum type and the Allium type. The diversity in the female gametophyte development in S. hexandrum reveals megagametogenesis may be influenced by altitude and be of great significance to its adaptability and evolution. In the Podophyllum group, Sinopodophyllum is more advanced than Diphylleia and Dysosma, where the female gametophyte development conforms to the Polygonum type. In addition, the results of this study directly provide evidence that the disporous Allium-type is derived from the monosporous Polygonum-type.