Properties of meso-tetra-(3-N-methylpyridyl)porphyrin and its complex formation reaction with lead (Ⅱ) wore studied, and a now highly sensitive method for spectre-photometric determination of micro amounts of lead has been developed, utilizing the Soret band of the lead-T(3-MPy)P complex. The complex formation reaction in aqueous medium is very rapid at room temperature. The Soret band of the complex lies at 472 nm. A straight line calibration curve is obtained up to at last 800 ppb of lead. Apparent molar absorption coefficient is 2.53×10⁵. Interference duo to other ions are examined and their tolerance limits are also shown.