The relationship between the population dynamics of the tea pink mite, Acaphylla theae, and various ecological factors were studied. Under favorable condition, the relationship of the fecundity of the mite (Y, head per head) and the cumulation of effective temperature (X, day degree) could be modeled by the equation: Y=3×10^-7X³+0.0006X²+0.0164X+0.969. The development rate of the mite population was decreased when the temperature went below 18℃ or above 27℃. The most favorable relative humidity (RH) for the mite was between 75% and 90%. If RH went below 50% or above 95%, the development rate of population would be significantly decreased even stopped. There was a negative relationship between the development rate of population and precipitation or rainfall intensity. The amounts of mite on one bud 3 leaves shoot, one bud 4 leaves shoot and mature leaf were 70%, 55%, 27% of those on one bud 2 leaves shoot respectively, so the development rate of population became slower as the tea plant shoot became older. The mite development rate of population would not be affected when the initial density of mite was lower than 56.4 head per leaf, whereas it would be decreased as the density increased when the initial density was higher than 102.2 head per leaf. The natural enemies of the mite were seldom found in the field, so the effect of the natural enemies on the mite development of population was insignificant. The effect of sunshine on the population development of mite was not significant.