3. The function $f(x)$ is defined on $\mathbf{R}$ as an odd function, and $f(2)=0$. For any $x \in \mathbf{R}$, $f(x+4)=f(x)+f(4)$ holds, $f(2002)=$ $\qquad$ .
3. 0 .

Let $x=-2$, then $f(2)=f(-2)+f(4)$, which means $f(4)=2 f(2)=0$, so $f(x+4)=f(x)$, the period of $f(x)$ is 4, hence $f(2002)=f(500 \times 4+2)=f(2)=0$.