Abstract: In order to define the effects of biochar on the seed germination and seedling growth, maize was used as experimental material for germination culture experiment. The seeds were cultured in light culture under the control, bamboo leaf biochar, tobacco stalk biochar and wheat straw biochar treatment. The germination potential, germination rate, germination index, and root morphology of the seedlings were measured respectively. Results showed that biochar had no significant effect on maize seed germination, but had significant inhibitory effect on the root development of maize seedlings. The inhibition rates of bamboo leaf, tobacco stalk and wheat straw biochar to maize root length were 14.4%, 59.7% and 37.3% respectively. This experiment can be initially concluded that: under the conditions of biochar, the sensitivity of maize seed germination is less than the root elongation of seedlings; and the root inhibition rate can be used as a good test method for the assessment of phytotoxicity of biochar.