Abstract: To discover new structural hits, based on the important role of pyrazole ring and fragment of pyridinone carboxylic acid in drug design, novel title pyrazolo3,4-bpyridine-4-one-5-carboxylic acid derivatives (10a-10p) were designed and synthesized, the structures were confirmed by spectral data and elemental analyses. The antibacterial and antitumor activities were evaluated by the measured minimum inhibitory concentration (MIC) values against the tested four strains and half inhibitory concentration (IC₅₀) values against the tested four cancer cells, respectively. The results displayed markedly poor antibacterial activity and observably potent antitumor activity. In particularly, the title difluorophenyl (10d, 10e, 10f), pyridyl (10j), ethyl (10k) and cycloproyl (10l) compounds exhibited comparable activity against Capan-1 and A549 cells to that of the comparison doxorubicin. Thus, pyrazolo3,4-bpyridine-4-one-5-carboxylic acid derivatives as promising antitumor hits need to be developed.