Phytochemical constituents were isolated from bitter melon (the fruits of Momordica charantia) through open column chromatography. Their structures were identified as ${eta}$-sitosterol (1), (23E)-$5{eta}$,19-epoxycucurbita-6,23-diene-$3{eta}$,25-diol (2), daucosterol (3), uracil (4), and allantoin (5) by interpretation of spectroscopic analysis including MS and $^1H$- & $^{13}C$-NMR. Among them, allantoin (5) was isolated from this plant for the first time.