An aim of a thesis is to measure plasma parameter using a technique of plasma diagnostics(Rogowski coil, loop coil, Langmuir probe, etc) on the KAIST tokamak. Diagnostics is to measure plasma parameter(temperature, density, plasma potential, etc) analyzing a characteristic of plasma. Plasma current and loop voltage is measured by a magnetic pick-up coil(Rogowski coil and loop coil). Plasma current is $3 \sim8$ kA, and plasma break down at loop voltage $8\sim 12$ V on the KAIST tokamak. $H_{\sigma}$ line emittng from plasma is measured by photo multiplier tube. It is seen that the intesity of $H_{\alpha}$ line abruptly increase when plasma break down. The density of plama is measured by a microwave interferometer and the temperature of plasma is measured by a Langmuir probe(single probe). Plasma density is about the maximum $9\times10^{12} cm^{-3}$ at shot 286 and plasma temperature is about the largest 12 eV. Plasma density diagnosticed with Langmuir probe density diagnosed with Langmuir probe is about the maximum $9.2\times10^{12} cm^{-3}$. The position of plasma is measured by OMA(Optical Multichannel Analyzer). It is difficult position to understand the physical meaning because of the data of time integral and space integral. But if we use photo-diode of ten channel, we can settle the problem of time integral.
