Abstract: The damage of retrograde condensate pollution on condensate gas wells is a very important problem while condensate reservoirs are developed, which decreases the productivity of the condensate gas wells and causes the slope of quadric formnegative. With the geologic feature of someone condensate gas field, the article deeply studies the special phenomena that the retrograde condensate separates out by numerical simulation technology. The conclusions show that the retrograde condensate badly influences productivity. It is shown that the retrograde condensate greatly consumes energy to reduce productivity, and causes that the productivity based on quadric form are smaller than factual 1 （the decline of production capacity could amount 31%）, and sometimes bring about the slope of quadric form negative. The paper researches into the quantitative influence of the retrograde condensate is obtained. It guides that we look for reasonable productivity equation of condensate gas well.