Here, the electrochemical carbon sensor modified with titanium oxide (TiO2) nanoparticles and 5-Chloro, 2, 4-dihydroxyphenyl imidazo [4,5-d] [1,3] thiazin 7(3H)-one, an imidazole derivative, (CHIT) was fabricated for hydroxylamine (HX) determination. After optimization, some kinetic parameters related to CHIT were obtained. The observations revealed that using CHIT with TiO2 nanoparticle affected in lowering value of oxidation potential and increasing of oxidation peak currents, which provides higher sensitivity. According to these results CHIT-TiO2-CPE sensor possess the linear range (0.5–850 μM) (0.5-40 and 40-850 μM) and a low detection limit (DL) 0.08 μM according to 3sb/m. Also CHIT-TiO2-CPE was used for determination of phenol in the range of 90 μM to 800 μM in the presence of various concentration of HX. Also, the CHIT-TiO2-CPE was used in water samples, successfully.