The atmospheric corrosion of reinforcement steel phenomenon has been frequently investigated under accelerated exposure, throughout diagnostic studies on site and no so much study under natural environmental conditions using probes with different concrete qualities. An exposure site placed at 20 m from the seashore without the presence of artificial of natural screening in the Havana northern coast was selected. Six reinforced concrete probes with water/cement ratios of 0.4, 0.5 and 0.6 and a wooden with four atmospheric pollutants devices, two of them for chloride deposition and the other two for the sulphur compounds deposition were placed in the exposure site. In each probe were placed two reinforced steel with recovering thickness of 20 and 40 mm. The increment of the atmospheric corrosion of the reinforcement steel inside in the time; permit us to estimate the service life of the structures that will be built in coastal zones of Havana with a high level of corrosion aggressivity of the atmosphere and without the presence of any kind of artificial screening. The reinforced concrete probes with water/cement ratios of 0.5, 0.6 and 0.4only with 2 cm of concrete coating thickness do not assure a suitable primary protection as a physic barrier, between the concrete structures.