The possibility of using the solid base as the pyrolysis catalyst to synthesize chemicals from duckweed (Lemna minor) was explored. Thermogravimetric analyses indicated that the conversion of duckweed in slow pyrolysis was approximately 60 wt%. Direct pyrolysis of duckweed could form various hydrocarbons and precursors for industrious products. When pyrolyzing this species with the solid base catalyst, new chemicals such as 3-methyl-butanal, cyclobutanol, 2-methyl-1H-pyrrole, ethylbenzene, 2-pyrrolidinone, and 4-ethyl-phenol were synthesized. The results indicated that the application of the solid base in pyrolysis mainly enhanced the alkyl substitution reactions and could direct complex pyrolysis reactions to preferred products.