Abstract: Studied here in the article are the effects by the heat treatment temperature and the holding duration on the microstructure and the tensile property of the 15-15Ti cladding tube. As a result the facts as follows are revealed. The grain size of the 15-15Ti stainless steel is getting larger and larger along with the rising of the heat treatment temperature and the extending of the holding duration;in case of the holding duration as 5~60 min,the grain enlargement apparent activation energy is 419.03~502.17 kJ/mol;the relation between the average grain size and the holding duration is the parabolic relation,and following the rising of the temperature,the changing trend of the dynamic time exponential η is remaining the same firstly,and then getting increased;under different holding durations,the tensile strength changes as following the temperature and holding duration with a same trend basically,while gets decreased gradually along with rising of the temperature and extending of the holding duration;and under different heat treatment conditions,relation between the specified plasticity elongation strength and the average grain size is in compliance with the Hall-Petch relation.