An unexpected multi-component reaction of cyanothioacetamide with aldehyde and aminopyrazole under MWI was reported. Through this reaction,a series of pyrazolo[3,4-b]-pyridine derivatives was prepared in high yields via simple operational procedure. An unexpected multi-component reaction of cyanothioacetamide with aldehyde and aminopyrazole under MWI was reported. Through this reaction, a series of pyrazolo [3,4-b] -pyridine derivatives was prepared in high yield via simple operational procedure.