This study was carried out to study the in-vitro efficacy of different chemical fungicides leaf spot of marigold, caused by Alternaria alternata. The results of present study showed that the disease incidence from various locations of district Hyderabad Sindh was observed Ghangra Mori 35%, TandoHyder 30%, Rahooki 25%, Moosa Khatyan20%, and Hosri 15%. Upper limit disease occurrence was observed from Ghangra Mori and lower limit sickness was recorded from Hosri. The chemical fungicide Nativo observed 43%, 25.5% and 18.5% linear colony growth of Alternaria alternata at 100, 200 and 400 ppm, respectively. Aliete observed 52, 31.5 and 21 respectively. Carbandazm observed 52.5, 29.5 and 21mm respectively and Mancozeb observed 51, 28.5 and 20mm respectively. Lower limit growth of Alternaria alternata were judge in 400 ppm instead Nativo pursuited by Mancozeb, Carbandazm and Aliete, separately. In control there was 90mm was recorded. It was concluded that chemical fungicide ‘Nativo’ were full effective to stop the disperssion of Alternaria alternata in 400 ppm. Anytime the plant infusion, Neem infusion show good effect opposite linear colony growth of Alternaria alternata on 6% solution