Abstract: Capsella bursa-pastoris, Lepidium apetalum, Lagopsis supina and Viola prionantha are four common early spring plants in Taiyuan, Shanxi. The biomass dynamics during their growth and development processes were studied by using harvest method and regression analysis, moreover, the relationship between the biomass and time were analyzed by regression analysis. The results were as follows:(1)The regression equations between the biomass of C. bursa-pastoris fruits, L. apetalum stem, L. supina stem, V. prionantha stem and total and time are high significant. (2)Accumulation of photosynthetic products was used to produce large amount of seeds. As a result, the proportion of the mature fruit's biomass in total was fairly high, among which the maximum were C. bursa-pastoris 56.7%, L. apetalum 40.6%, L. supina 25.2% and of V. prionantha 18.1%, respectively. (3)It was suggested that most of the early spring plants grow rapidly in May. C. bursa-pastoris, L. apetalum and L. supina reached the climax of their biomass increment ratio during the end of April, whereas V. prionantha weight peaks took place during the middle of May.

Key words: early spring plant, biomass, dynamics, regression analysis