Oxygen and lithium isotopic compositions of whole rocks from ODP/IODP Hole 1256D were investigated. The upper about 1000 m extrusive basalts have higher oxygen isotope values(\begin{math}d{}\end{math}¹⁸O= 6.1- 9.2\textperthousand{})reflecting low temperature alteration at \begin{math}d{}\end{math}¹⁸O values from 3.0 to 6.0\textperthousand{}, which indicates alteration at high temperature (\begin{math}>\end{math}250\textdegree{}C). In the sheeted dike complex the whole rock \begin{math}d{}\end{math}¹⁸O values gradually decrease to a minimum of 3.0\textperthousand{} at \textasciitilde{}1350 mbsf and then increase toward fresh MORB \begin{math}d{}\end{math}¹⁸O value at the top of plutonic section. A down-hole profile of lithium concentrations mimics the oxygen isotope variation trend. Above the depth of \textasciitilde{} 900 mbsf the oceanic crust is dominated by rocks with enriched lithium content relative to fresh MORB (3ppm) and below that depth lithium concentrations gradually decrease with depth and then slowly increase toward the value for unaltered MORBs with a kink at \textasciitilde{} 1350 mbsf. Li isotopes behave differently. The upper volcanic zone is characterized by a spread of \begin{math}d{}\end{math}⁷Li from depleted to enriched values. Cooper et al.(2008) showed that most of the whole-rocks in this zone are within the range of \begin{math}d{}\end{math}⁷Li for fresh EPR samples(3.1-5.2 \textperthousand{}), with a few of the samples having lower or slightly higher \begin{math}d{}\end{math}⁷Li, although the vein minerals from Leg 206 samples all have high\begin{math}d{}\end{math}⁷Li. The majority of the massive flows and sheeted dikes show enriched \begin{math}d{}\end{math}⁷Li values. In the deeper sheeted dike complex, \begin{math}d{}\end{math}⁷Li values show a steep gradient from enrichment to depletion and then return to values for fresh MORBs after several tens of meters in the plutonic section. This indicates a rapid change of the hydrothermal system from water domination (w/r\begin{math}>\end{math}1) to rock domination(w/r\begin{math}d{}\end{math}⁷Li values of whole rocks occurs at a much deeper depth at \textasciitilde{} 1300 mbsf. Whole rocks at the kink position around 1350 mbsf - defined by the down-hole variation of \begin{math}d{}\end{math}¹⁸O values - also show the lowest \begin{math}d{}\end{math}⁷Li values in the lower sheeted dike complex. The kink position probably marks the transition from a fluid dominated system to a rock dominated system, which may indicate the presence of a zone of hydrothermal upwelling at the top of plutonic rocks.