Abstract:The content of total proteins (TP) in the mature cotyledon of red lotus (Nelumbo nucifera Gaertn) reached 24.35 g/100 g dry sample; the accumulation pattern of its storage proteins (SP) was similar to that of Leguminosae seeds, i.e. with increasing maturity, the content of SP reached abruptly to more than 86% of the TP content. Result from optical densitometry of protein SDS-PAGE in different developmental stages of the lotus cotyledon indicated that the lotus cotyledon SP included 12 major subunits (SP 1~12). In respect of MW and accumulation time, they might be divided into 3 groups. Group A had 2 subunits with the highest MW (98 kD and 93 kD) and the latest accumulation time that had the highest SP content. Group B had 3 subunits with moderate MW of 55 ~ 50 kD, their earliest accumulation time, and least SP content. And group C included 7 subunits with the lowest MW of 27~ 14 kD, moderately early accumulation time, and high SP comparatively content. By comparing the results of SDS-PAGE analysis among different varieties and organs of lotus, there was a common metabolic protein subunit with multiply connected peak. Its MW was 68 kD, which might be a common subunit of the lotus species.