The absorption spectrum of merocyanine (BTET) film deposited on a NaCl substrate showed a broad absorption band in the wavelength region between 450 nm and 550 nm and a narrow peak at 640 nm. The former bands were assigned to the absorption bands of alpha- and beta-form crystal, the latter peak was assigned to J-band. BTET film was composed of square-shaped and rectangular crystals grown epitaxially. The square-shaped crystal was composed of alpha-form and the rectangular crystal was composed of alpha-form and J-aggregate. The formation mechanism of J-aggregate in film was discussed.