Heterocyclic analogues of 1, 2, 3-oxadiazolium-5-olate along with pyrazole ring and isoxazole ring have been designed for antineoplastic evaluation. A series of novel 4-[5-(aryl)-4, 5-dihydro-(1H-pyrazole/1-phenylpyrazol/ isoxazole)-3-yl]-3-(4-methoxyphenyl)-1, 2, 3-oxadiazolium-5-olates has been synthesized and compounds (31d, 32d, 33d) evaluated antitumor activity against 60 human tumor cell lines. Each compound is exposed to 60 human tumor cell lines, including non small cell lung, colon, melanoma, prostate, ovarian, breast, and kidney cancers. Data reported as a mean graph of the percent growth inhibition of treated cells. Out of 60 human tumor cell lines, compound 33d is highly effective for non small cell lung cancer cell lines and melanoma (M14). Further designing with modifications and in vivo study of synthesized 1, 2, 3-oxadiazolium-5-olates may give a ray of light to search for a potent antitumor molecule.