Since the discovery of the millisecond pulsar in 1982,Six millisecond pulsars are known to be exist. They have extremely small period derivatives and several distinct characteristics. Some of them seem to be useful as time standard. Making use of the timing stabilities, an attempt to detect the cosmic background gravitational radiations has been made elsewhere. We have been considering to make such observations using the deep space tracking telescope in Usuda. Recently we detected the pulse from PSR 1937+21,which is the most promissing object for the timing observations. We also estimate the dispersion measure which is in agreement with the previous observations. we are designing a timing equipment to be used in regular observations in the near future.