Temporal acidity (pH) and electrical conductivity (EC) changes in runoff water determined through sediment traps established on unpaved (UPFR) and paved forest road (PFR) ditches and in an undisturbed (UA) forest land. Research was carried out one year with monthly samplings from November 2009 to October 2010. In runoff water, pH was changed between 5.15 pH and 7.32 pH, and EC was between 58.35 gS/cm and 198.09 gS/cm. Both EC and pH of runoff water showed significant variations among experiment sites and months. Runoff EC and pH sourced from PFR showed a significant relationship in regressions with same parameters of precipitation indicating that EC and pH of runoff sourced from paved forest road were related directly to precipitation chemistry. However, to indicate a definite trend or difference is difficult despite significant differences among road types and sampling times.