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From H\alpha narrow band observations, we identified three H\alpha emittingregions in the direction of Magellanic Stream IV (MS IV). They consist of threeparallel filaments with 2 arcmin width and 6 -- 30 arcmin length at 12 arcminintervals. The mean surface brightness of them is $\sim 2 \times 10^{-18}$ ergs$^{-1}$ cm$^{-2}$ arcsec$^{-2}$. Because of their low surface brightness, theregions were not detected in previous H\alpha surveys. In HI map, the positionof the filaments overlap MS, suggesting that they are parts of MS, but therealso exists a local HI structure. If the filaments associate with MS, the sizesare 30 pc $\times$ 100 -- 500 pc. The filaments lie at the leading edge of adownstream cloud, which supports a shock heating and its propagation (shockcascade) model for the ionizing source. If they are local objects, on the otherhand, Fossil Str\"omgren Trails of more than two stars is a possibleinterpretation, and the sizes would be 0.1 pc $\times$ 0.3 -- 1.5 pc at 180 pcdistance. The positional information of the H\alpha filaments presented in thisletter enables us future spectroscopic observations to clarify their nature.

Candidates of Halpha emitting regions in Magellanic Stream IV cloud