The purposes of the effective goal which aim of study English speaking to encourage and improve learners speak fluency and accurate of this research were: 1) to study and compare scores testing by the English speaking ability tests before and after studying through Communicative Tasks of undergraduate students using three communicative tasks at Kalasin University in Kalasin, Thailand, classified by high, medium, and low, according to their abilities of English speaking ability level and 2) to study the students’ feeling learning English speaking attitudes  towards teaching English speaking using Communicative Tasks. The sample consisted of 9 first-year undergraduate students at Kalasin University, Kalasin Province, Thailand in the second semester of the academic year 2017 classified by high, medium, and low proficiency level according to their abilities. The research was a one group pretest-posttest design. The research instruments included 12 lesson plans with English speaking using Communicative Tasks, an English speaking ability test consist of quizzesand an attitude questionnaire. The instrument employed were percentage that concern with scores of speaking English test focus on pretest and posttest, Mean, Standard Deviation, and t-test for Dependent Samples that examines toward English speaking test of the similar between a pretest and posttest. The findings for this research of the students’ leaning speaking English using Communicative Tasks were as follows: 1) the students’ pretest were 35.22 or 32.02 percent and increased English speaking skill toward posttest mean score on English speaking ability test were 94.56 or 85.96 percent respectively. The posttest score of the students’ leaning speaking using Communicative Tasks was significantly higher than that of the pretest.  2) The students’ feeling learning English using attitude towards teaching English speaking ability using Communicative Tasks was at a very good level(Χ =4.90). 

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