A model used to estimate the optical turbulence in the marine atmospheric surface layer is developed based on the similarity theory and some modifications of the theory under the extremely stable and unstable conditions, and some numerical analyses are done. It is found that the temperature fluctuation dominates the contributions to the optical turbulence when the temperature difference between the air and the sea surface is large. As the temperature difference becomes smaller, the moisture fluctuation contribution becomes dominative, especially in the infrared windows, with the lower air moisture, and the lower the air moisture, the stronger the optical turbulence. Accompanying the strengthening of the surface wind, the optical turbulence first becomes stronger with the weaker surface wind, then weaker with the stronger surface wind when the air is cooler than the sea surface, but generally becomes weaker with the air being warmer than the sea. The optical turbulence is stronger in the infrared window than that in the visible and near-infrared band when the air is cooler or slightly warmer than the sea, but they are comparable when the air is much warmer than the sea. Under the neutral and near-neutral conditions, the dependence of the vertical profile of the structure parameter of the air refractive index, C2n, on the vertical height obeys the -2/3 power law. As the surface stability becomes more stable (unstable), the absolute value of the negative power of the profile becomes smaller (bigger), and approaches to 0 (-4/3).