In this work we study the galaxy NGC4736, using narrow band interference filters imaging centered at the emission lines {Oii} {3727+3729}, Hβ, {Oiii} {5007}, Hα, {Sii} {6716+6730} and {Siii} {9070} and nearby continua. We have obtained sizes, positions, emission line absolute fluxes, and continua intensities for 90 Hii regions, mainly distributed in a ring-like structure of 3.2kpc in diameter. The Hα luminosities are in the range 37.3 <= log L_Hα <= 39.4 ergs(-1) . The Hii regions size distribution presents a characteristic diameter D_0 = 115pc and verifies the relation log (L_Hα ) ~D(3) . The temperature of the ionizing sources and the metallicity of the Hii regions are respectively in the ranges 3.410(4) <~T_⋆ <~ 4.010(4) K and 8.5 <~12 + log (O/H) <~9.3. The masses of the ionizing clusters are in the range 510(3) <~M_T/M_sun <~210(5) . The continua radial surface brightness distribution is better fitted by the superposition of a de Vaucouleurs', a thin and a thick exponential disk laws. The monochromatic colors show that outside the star forming ring the disk presents a younger stellar population than inside it. Tables 3 and 4 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html